Neoplasms of unspecified behavior (D49)

Browse all the diagnosis codes used for neoplasms of unspecified behavior (d49). For easy navigation, the diagnosis codes are sorted in alphabetical order and grouped by sections. Each section is clearly marked with its description, and the corresponding three-digit code range. This format makes it simple to browse diagnosis codes in this chapter or section and find what you're looking for. We've also added green checkmark icons to label billable codes, and red warning icons for non-billable ones. This makes it easy to identify which codes can be billed.

Clinical Information

Abruptio Placentae - Premature separation of the normally implanted PLACENTA from the UTERUS. Signs of varying degree of severity include UTERINE BLEEDING, uterine MUSCLE HYPERTONIA, and FETAL DISTRESS or FETAL DEATH.

Acalculous Cholecystitis - Inflammation of the GALLBLADDER wall in the absence of GALLSTONES.

Ampulla of Vater - A dilation of the duodenal papilla that is the opening of the juncture of the COMMON BILE DUCT and the MAIN PANCREATIC DUCT, also known as the hepatopancreatic ampulla.

Ankyloglossia - A severe congenital restriction of TONGUE movement, resulting from fusion or adherence of the tongue to the floor of the mouth. In partial ankyloglossia (tongue-tie) the LINGUAL FRENUM is abnormally short, or is attached too close to the tip of the tongue. OMIM: 106280

Annexin A3 - A protein of the annexin family that catalyzes the conversion of 1-D-inositol 1,2-cyclic phosphate and water to 1-D-myo-inositol 1-phosphate.

Annexin A4 - Protein of the annexin family originally isolated from the electric organ of the electric ray Torpedo marmorata. It has been found in a wide range of mammalian tissue where it is localized to the apical membrane of polarized EPITHELIAL CELLS.

Annexin A5 - A protein of the annexin family isolated from human PLACENTA and other tissues. It inhibits cytosolic PHOSPHOLIPASE A2, and displays anticoagulant activity.

Anterior Hypothalamic Nucleus - Loose heterogeneous collection of cells in the anterior hypothalamus, continuous rostrally with the medial and lateral PREOPTIC AREAS and caudally with the TUBER CINEREUM.

Anterior Thalamic Nuclei - Three nuclei located beneath the dorsal surface of the most rostral part of the thalamus. The group includes the anterodorsal nucleus, anteromedial nucleus, and anteroventral nucleus. All receive connections from the MAMILLARY BODY and BRAIN FORNIX, and project fibers to the CINGULATE BODY.

Aponeurosis - The flattened and/or expanded “tendon-like” dense fibrous connective tissue that connects skeletal muscles to each other or to bone.

Appendiceal Neoplasms - Tumors or cancer of the APPENDIX.

Appendix - A worm-like blind tube extension from the CECUM.

Arachnoid - A delicate membrane enveloping the brain and spinal cord. It lies between the PIA MATER and the DURA MATER. It is separated from the pia mater by the subarachnoid cavity which is filled with CEREBROSPINAL FLUID.

Arachnoid Cysts - Intracranial or spinal cavities containing a cerebrospinal-like fluid, the wall of which is composed of arachnoidal cells. They are most often developmental or related to trauma. Intracranial arachnoid cysts usually occur adjacent to arachnoidal cistern and may present with HYDROCEPHALUS; HEADACHE; SEIZURES; and focal neurologic signs. (From Joynt, Clinical Neurology, 1994, Ch44, pp105-115)

Arachnoiditis - Acute or chronic inflammation of the arachnoid membrane of the meninges most often involving the spinal cord or base of the brain. This term generally refers to a persistent inflammatory process characterized by thickening of the ARACHNOID membrane and dural adhesions. Associated conditions include prior surgery, infections, trauma, SUBARACHNOID HEMORRHAGE, and chemical irritation. Clinical features vary with the site of inflammation, but include cranial neuropathies, radiculopathies, and myelopathies. (From Joynt, Clinical Neurology, 1997, Ch48, p25)

Arcuate Nucleus of Hypothalamus - A nucleus located in the middle hypothalamus in the most ventral part of the THIRD VENTRICLE near the entrance of the infundibular recess. Its small cells are in close contact with the EPENDYMA.

Arrestin - A 48-Kd protein of the outer segment of the retinal rods and a component of the phototransduction cascade. Arrestin quenches G-protein activation by binding to phosphorylated photolyzed rhodopsin. Arrestin causes experimental autoimmune uveitis when injected into laboratory animals.

ATP Binding Cassette Transporter, Subfamily A, Member 4 - An ATP binding cassette sub-family A transporter that translocates 11-cis and all-trans isomers of N-retinylidene-phosphatidylethanolamine (RETINOIDS) from the extracellular surface to the cytoplasmic membrane surface of RETINAL ROD CELLS and RETINAL CONE CELLS. Mutations in the ABCA4 gene are associated with Stargardt Disease 1, a hereditary juvenile form of MACULAR DEGENERATION.

Bariatric Surgery - Surgical procedures aimed at affecting metabolism and producing major WEIGHT REDUCTION in patients with MORBID OBESITY.

Barrett Esophagus - A condition with damage to the lining of the lower ESOPHAGUS resulting from chronic acid reflux (ESOPHAGITIS, REFLUX). Through the process of metaplasia, the squamous cells are replaced by a columnar epithelium with cells resembling those of the INTESTINE or the salmon-pink mucosa of the STOMACH. Barrett's columnar epithelium is a marker for severe reflux and precursor to ADENOCARCINOMA of the esophagus.

Basal Ganglia - Large subcortical nuclear masses derived from the telencephalon and located in the basal regions of the cerebral hemispheres.

Basal Ganglia Cerebrovascular Disease - A pathological condition caused by impaired blood flow in the basal regions of cerebral hemispheres (BASAL GANGLIA), such as INFARCTION; HEMORRHAGE; or ISCHEMIA in vessels of this brain region including the lateral lenticulostriate arteries. Primary clinical manifestations include involuntary movements (DYSKINESIAS) and muscle weakness (HEMIPARESIS).

Basal Ganglia Diseases - Diseases of the BASAL GANGLIA including the PUTAMEN; GLOBUS PALLIDUS; claustrum; AMYGDALA; and CAUDATE NUCLEUS. DYSKINESIAS (most notably involuntary movements and alterations of the rate of movement) represent the primary clinical manifestations of these disorders. Common etiologies include CEREBROVASCULAR DISORDERS; NEURODEGENERATIVE DISEASES; and CRANIOCEREBRAL TRAUMA.

Basal Ganglia Hemorrhage - Bleeding within the subcortical regions of cerebral hemispheres (BASAL GANGLIA). It is often associated with HYPERTENSION or ARTERIOVENOUS MALFORMATIONS. Clinical manifestations may include HEADACHE; DYSKINESIAS; and HEMIPARESIS.

Biliary Dyskinesia - A motility disorder characterized by biliary COLIC, absence of GALLSTONES, and an abnormal GALLBLADDER ejection fraction. It is caused by gallbladder dyskinesia and/or SPHINCTER OF ODDI DYSFUNCTION.

Blood-Retinal Barrier - A specialized transport barrier, in the EYE, formed by the retinal pigment EPITHELIUM, and the ENDOTHELIUM of the BLOOD VESSELS of the RETINA. TIGHT JUNCTIONS joining adjacent cells keep the barrier between cells continuous.

Bluetongue - A reovirus infection, chiefly of sheep, characterized by a swollen blue tongue, catarrhal inflammation of upper respiratory and gastrointestinal tracts, and often by inflammation of sensitive laminae of the feet and coronet.

Body Piercing - The perforation of an anatomical region for the wearing of jewelry.

Brachial Plexus - The large network of nerve fibers which distributes the innervation of the upper extremity. The brachial plexus extends from the neck into the axilla. In humans, the nerves of the plexus usually originate from the lower cervical and the first thoracic spinal cord segments (C5-C8 and T1), but variations are not uncommon.

Brachial Plexus Block - A blocking of NEURAL CONDUCTION in the network of nerve fibers innervating the UPPER EXTREMITY.

Brachial Plexus Neuritis - A syndrome associated with inflammation of the BRACHIAL PLEXUS. Clinical features include severe pain in the shoulder region which may be accompanied by MUSCLE WEAKNESS and loss of sensation in the upper extremity. This condition may be associated with VIRUS DISEASES; IMMUNIZATION; SURGERY; heroin use (see HEROIN DEPENDENCE); and other conditions. The term brachial neuralgia generally refers to pain associated with brachial plexus injury. (From Adams et al., Principles of Neurology, 6th ed, pp1355-6)

Brachial Plexus Neuropathies - Diseases of the cervical (and first thoracic) roots, nerve trunks, cords, and peripheral nerve components of the BRACHIAL PLEXUS. Clinical manifestations include regional pain, PARESTHESIA; MUSCLE WEAKNESS, and decreased sensation (HYPESTHESIA) in the upper extremity. These disorders may be associated with trauma (including BIRTH INJURIES); THORACIC OUTLET SYNDROME; NEOPLASMS; NEURITIS; RADIOTHERAPY; and other conditions. (From Adams et al., Principles of Neurology, 6th ed, pp1351-2)

Broad Ligament - A broad fold of peritoneum that extends from the side of the uterus to the wall of the pelvis.

Cadherins - Calcium-dependent cell adhesion proteins. They are important in the formation of ADHERENS JUNCTIONS between cells. Cadherins are classified by their distinct immunological and tissue specificities, either by letters (E- for epithelial, N- for neural, and P- for placental cadherins) or by numbers (cadherin-12 or N-cadherin 2 for brain-cadherin). Cadherins promote cell adhesion via a homophilic mechanism as in the construction of tissues and of the whole animal body.

Carcinoma, Pancreatic Ductal - Carcinoma that arises from the PANCREATIC DUCTS. It accounts for the majority of cancers derived from the PANCREAS.

Cauda Equina - The lower part of the SPINAL CORD consisting of the lumbar, sacral, and coccygeal nerve roots.

Cauda Equina Syndrome - Compressive lesion affecting the nerve roots of the CAUDA EQUINA (e.g., compression, herniation, inflammation, rupture, or stenosis), which controls the function of the bladder and bowel. Symptoms may include neurological dysfunction of bladder or bowels, loss of sexual sensation and altered sensation or paralysis in the lower extremities.

Cementoma - An odontogenic fibroma in which cells have developed into cementoblasts and which consists largely of cementum.

Cerebrospinal Fluid Rhinorrhea - Discharge of cerebrospinal fluid through the nose. Common etiologies include trauma, neoplasms, and prior surgery, although the condition may occur spontaneously. (Otolaryngol Head Neck Surg 1997 Apr;116(4):442-9)

Cholecystitis - Inflammation of the GALLBLADDER; generally caused by impairment of BILE flow, GALLSTONES in the BILIARY TRACT, infections, or other diseases.

Chorionic Villi - Threadlike vascular projections of the chorion. Chorionic villi may be free or embedded within the DECIDUA forming the site for exchange of substances between fetal and maternal blood (PLACENTA).

Choroid - The thin, highly vascular membrane covering most of the posterior of the eye between the RETINA and SCLERA.

Choroid Diseases - Disorders of the choroid including hereditary choroidal diseases, neoplasms, and other abnormalities of the vascular layer of the uvea.

Choroid Hemorrhage - Hemorrhage from the vessels of the choroid.

Choroid Neoplasms - Tumors of the choroid; most common intraocular tumors are malignant melanomas of the choroid. These usually occur after puberty and increase in incidence with advancing age. Most malignant melanomas of the uveal tract develop from benign melanomas (nevi).

Choroid Plexus - A villous structure of tangled masses of BLOOD VESSELS contained within the third, lateral, and fourth ventricles of the BRAIN. It regulates part of the production and composition of CEREBROSPINAL FLUID.

Choroid Plexus Neoplasms - Benign or malignant tumors which arise from the choroid plexus of the ventricles of the brain. Papillomas (see PAPILLOMA, CHOROID PLEXUS) and carcinomas are the most common histologic subtypes, and tend to seed throughout the ventricular and subarachnoid spaces. Clinical features include headaches, ataxia and alterations of consciousness, primarily resulting from associated HYDROCEPHALUS. (From Devita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2072; J Neurosurg 1998 Mar;88(3):521-8)

Choroidal Effusions - Finding of fluid accumulation between the CHOROID and the SCLERA.

Choroidal Neovascularization - A pathological process consisting of the formation of new blood vessels in the CHOROID.

Choroideremia - An X chromosome-linked abnormality characterized by atrophy of the choroid and degeneration of the retinal pigment epithelium causing night blindness.

Choroiditis - Inflammation of the choroid.

Ciliary Body - A ring of tissue extending from the scleral spur to the ora serrata of the RETINA. It consists of the uveal portion and the epithelial portion. The ciliary muscle is in the uveal portion and the ciliary processes are in the epithelial portion.

Clavicle - A bone on the ventral side of the shoulder girdle, which in humans is commonly called the collar bone.

Cleft Palate - Congenital fissure of the soft and/or hard palate, due to faulty fusion.

Clitoris - An erectile structure homologous with the penis, situated beneath the anterior labial commissure, partially hidden between the anterior ends of the labia minora.

Coccyx - The last bone in the VERTEBRAL COLUMN in tailless primates considered to be a vestigial tail-bone consisting of three to five fused VERTEBRAE.

Colon - The segment of LARGE INTESTINE between the CECUM and the RECTUM. It includes the ASCENDING COLON; the TRANSVERSE COLON; the DESCENDING COLON; and the SIGMOID COLON.

Cone-Rod Dystrophies - Genetically heterogeneous and sometimes syndromic (e.g., BARDET BIEDL SYNDROME; and SPINOCEREBELLAR ATAXIA TYPE 7) retinopathies with initial RETINAL CONE involvement. They are characterized by decreased VISUAL ACUITY; COLOR VISION DEFECTS; progressive loss of peripheral vision and night blindness.

Conjunctiva - The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball.

Conjunctival Diseases - Diseases involving the CONJUNCTIVA.

Conjunctival Neoplasms - Tumors or cancer of the CONJUNCTIVA.

Contraceptive Devices, Female - Contraceptive devices used by females.

Cord Blood Stem Cell Transplantation - Transplantation of STEM CELLS collected from the fetal blood remaining in the UMBILICAL CORD and the PLACENTA after delivery. Included are the HEMATOPOIETIC STEM CELLS.

Costal Cartilage - Bars of HYALINE CARTILAGE extending from the anterior ends of the upper RIBS. They attach to the STERNUM directly or indirectly by connecting to upper costal cartilage that attaches to the STERNUM. Costal cartilages extend the ribs anteriorly and contribute to the enhanced elasticity of the THORACIC WALL.

Cyclic Nucleotide Phosphodiesterases, Type 6 - A cyclic nucleotide phosphodiesterase subfamily that is highly specific for CYCLIC GMP. It is found predominantly in the outer segment PHOTORECEPTOR CELLS of the RETINA. It is comprised of two catalytic subunits, referred to as alpha and beta, that form a dimer. In addition two regulatory subunits, referred to as gamma and delta, modulate the activity and localization of the enzyme.

Cystic Fibrosis - An autosomal recessive genetic disease of the EXOCRINE GLANDS. It is caused by mutations in the gene encoding the CYSTIC FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR expressed in several organs including the LUNG, the PANCREAS, the BILIARY SYSTEM, and the SWEAT GLANDS. Cystic fibrosis is characterized by epithelial secretory dysfunction associated with ductal obstruction resulting in AIRWAY OBSTRUCTION; chronic RESPIRATORY INFECTIONS; PANCREATIC INSUFFICIENCY; maldigestion; salt depletion; and HEAT PROSTRATION.

Dermatomyositis - A subacute or chronic inflammatory disease of muscle and skin, marked by proximal muscle weakness and a characteristic skin rash. The illness occurs with approximately equal frequency in children and adults. The skin lesions usually take the form of a purplish rash (or less often an exfoliative dermatitis) involving the nose, cheeks, forehead, upper trunk, and arms. The disease is associated with a complement mediated intramuscular microangiopathy, leading to loss of capillaries, muscle ischemia, muscle-fiber necrosis, and perifascicular atrophy. The childhood form of this disease tends to evolve into a systemic vasculitis. Dermatomyositis may occur in association with malignant neoplasms. (From Adams et al., Principles of Neurology, 6th ed, pp1405-6)

Diaphragm - The musculofibrous partition that separates the THORACIC CAVITY from the ABDOMINAL CAVITY. Contraction of the diaphragm increases the volume of the thoracic cavity aiding INHALATION.

Diaphragmatic Eventration - A congenital abnormality characterized by the elevation of the DIAPHRAGM dome. It is the result of a thinned diaphragmatic muscle and injured PHRENIC NERVE, allowing the intra-abdominal viscera to push the diaphragm upward against the LUNG.

Diverticulosis, Stomach - A pathological condition characterized by the presence of a number of GASTRIC DIVERTICULA in the STOMACH.

Diverticulum, Stomach - Saccular, outward protrusion of all or a portion of the wall of the STOMACH.

Duodenal Neoplasms - Tumors or cancer of the DUODENUM.

Duodenum - The shortest and widest portion of the SMALL INTESTINE adjacent to the PYLORUS of the STOMACH. It is named for having the length equal to about the width of 12 fingers.

Electronic Nose - A device used to detect airborne odors, gases, flavors, volatile substances or vapors.

Empty Sella Syndrome - A condition when the SELLA TURCICA is not filled with pituitary tissue. The pituitary gland is either compressed, atrophied, or removed. There are two types: (1) primary empty sella is due a defect in the sella diaphragm leading to arachnoid herniation into the sellar space; (2) secondary empty sella is associated with the removal or treatment of PITUITARY NEOPLASMS.

Endocardium - The innermost layer of the heart, comprised of endothelial cells.

Ependymoglial Cells - The macroglial cells of EPENDYMA. They are characterized by bipolar cell body shape and processes that contact BASAL LAMINA around blood vessels and/or the PIA MATER and the CEREBRAL VENTRICLES. Muller cells of the RETINA are included based on similar microenvironmental contacts and morphology.

Epididymis - The convoluted cordlike structure attached to the posterior of the TESTIS. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of SPERMATOZOA.

Epiglottis - A thin leaf-shaped cartilage that is covered with LARYNGEAL MUCOSA and situated posterior to the root of the tongue and HYOID BONE. During swallowing, the epiglottis folds back over the larynx inlet thus prevents foods from entering the airway.

Esophageal Motility Disorders - Disorders affecting the motor function of the UPPER ESOPHAGEAL SPHINCTER; LOWER ESOPHAGEAL SPHINCTER; the ESOPHAGUS body, or a combination of these parts. The failure of the sphincters to maintain a tonic pressure may result in gastric reflux of food and acid into the esophagus (GASTROESOPHAGEAL REFLUX). Other disorders include hypermotility (spastic disorders) and markedly increased amplitude in contraction (nutcracker esophagus).

Esophageal Mucosa - Circular innermost layer of the ESOPHAGUS wall that mediates esophageal PERISTALSIS which pushes ingested food bolus toward the stomach.

Esophageal Neoplasms - Tumors or cancer of the ESOPHAGUS.

Esophagogastric Junction - The area covering the terminal portion of ESOPHAGUS and the beginning of STOMACH at the cardiac orifice.

Esophagus - The muscular membranous segment between the PHARYNX and the STOMACH in the UPPER GASTROINTESTINAL TRACT.

Eustachian Tube - A narrow passageway that connects the upper part of the throat to the TYMPANIC CAVITY.

Eutheria - Mammals which nourish their young in utero by means of a complex placenta, and give birth to their young alive. They include PRIMATES; CARNIVORA, WHALES; RUMINANTS; BATS; and RODENTS.

Fasciculation - Involuntary contraction of the muscle fibers innervated by a motor unit. Fasciculations may be visualized as a muscle twitch or dimpling under the skin, but usually do not generate sufficient force to move a limb. They may represent a benign condition or occur as a manifestation of MOTOR NEURON DISEASE or PERIPHERAL NERVOUS SYSTEM DISEASES. (Adams et al., Principles of Neurology, 6th ed, p1294)

Folate Receptor 2 - A subtype of GPI-anchored folate receptors that is expressed in PLACENTA and hematopoietic cells.

Foreskin - The double-layered skin fold that covers the GLANS PENIS, the head of the penis.

Gallbladder - A storage reservoir for BILE secretion. Gallbladder allows the delivery of bile acids at a high concentration and in a controlled manner, via the CYSTIC DUCT to the DUODENUM, for degradation of dietary lipid.

Gallbladder Diseases - Diseases of the GALLBLADDER. They generally involve the impairment of BILE flow, GALLSTONES in the BILIARY TRACT, infections, neoplasms, or other diseases.

Gallbladder Emptying - A process whereby bile is delivered from the gallbladder into the duodenum. The emptying is caused by both contraction of the gallbladder and relaxation of the sphincter mechanism at the choledochal terminus.

Gallbladder Neoplasms - Tumors or cancer of the gallbladder.

Gastric Absorption - Uptake of substances via the stomach.

Gastric Antral Vascular Ectasia - A distinct vascular lesion in the PYLORIC ANTRUM that is characterized by tortuous dilated blood vessels (ectasia) radiating outward from the PYLORUS. The vessel pattern resembles the stripes on the surface of a watermelon. This lesion causes both acute and chronic GASTROINTESTINAL HEMORRHAGE.

Gastric Dilatation - Abnormal distention of the STOMACH due to accumulation of gastric contents that may reach 10 to 15 liters. Gastric dilatation may be the result of GASTRIC OUTLET OBSTRUCTION; ILEUS; GASTROPARESIS; or denervation.

Gastric Fistula - Abnormal passage communicating with the STOMACH.

Gastric Stump - That portion of the stomach remaining after gastric surgery, usually gastrectomy or gastroenterostomy for cancer of the stomach or peptic ulcer. It is a common site of cancer referred to as stump cancer or carcinoma of the gastric stump.

Gastrointestinal Contents - The contents included in all or any segment of the GASTROINTESTINAL TRACT.

Globus Pallidus - The representation of the phylogenetically oldest part of the corpus striatum called the paleostriatum. It forms the smaller, more medial part of the lentiform nucleus.

Glossitis, Benign Migratory - An idiopathic disorder of the tongue characterized by the loss of filiform papillae leaving reddened areas of circinate macules bound by a white band. The lesions heal, then others erupt.

Glottis - The vocal apparatus of the larynx, situated in the middle section of the larynx. Glottis consists of the VOCAL FOLDS and an opening (rima glottidis) between the folds.

Hep G2 Cells - A human liver tumor cell line used to study a variety of liver-specific metabolic functions.

Hepatoblastoma - A malignant neoplasm occurring in young children, primarily in the liver, composed of tissue resembling embryonal or fetal hepatic epithelium, or mixed epithelial and mesenchymal tissues. (Stedman, 25th ed)

Hernia, Diaphragmatic - Protrusion of abdominal structures into the THORAX as a result of congenital or traumatic defects in the respiratory DIAPHRAGM.

Hernia, Diaphragmatic, Traumatic - The type of DIAPHRAGMATIC HERNIA caused by TRAUMA or injury, usually to the ABDOMEN.

Hernias, Diaphragmatic, Congenital - Protrusion of abdominal structures into the THORAX as a result of embryologic defects in the DIAPHRAGM often present in the neonatal period. It can be isolated, syndromic, non-syndromic or be a part of chromosome abnormality. Associated pulmonary hypoplasia and PULMONARY HYPERTENSION can further complicate stabilization and surgical intervention.

Hypothalamic Area, Lateral - Area in the hypothalamus bounded medially by the mammillothalamic tract and the anterior column of the FORNIX (BRAIN). The medial edge of the INTERNAL CAPSULE and the subthalamic region form its lateral boundary. It contains the lateral hypothalamic nucleus, tuberomammillary nucleus, lateral tuberal nuclei, and fibers of the MEDIAL FOREBRAIN BUNDLE.

Hypothalamic Neoplasms - Benign and malignant tumors of the HYPOTHALAMUS. Pilocytic astrocytomas and hamartomas are relatively frequent histologic types. Neoplasms of the hypothalamus frequently originate from adjacent structures, including the OPTIC CHIASM, optic nerve (see OPTIC NERVE NEOPLASMS), and pituitary gland (see PITUITARY NEOPLASMS). Relatively frequent clinical manifestations include visual loss, developmental delay, macrocephaly, and precocious puberty. (From Devita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2051)

Hypothalamus - Ventral part of the DIENCEPHALON extending from the region of the OPTIC CHIASM to the caudal border of the MAMMILLARY BODIES and forming the inferior and lateral walls of the THIRD VENTRICLE.

Hypothalamus, Anterior - The front portion of the HYPOTHALAMUS separated into the preoptic region and the supraoptic region. The preoptic region is made up of the periventricular GRAY MATTER of the rostral portion of the THIRD VENTRICLE and contains the preoptic ventricular nucleus and the medial preoptic nucleus. The supraoptic region contains the PARAVENTRICULAR HYPOTHALAMIC NUCLEUS, the SUPRAOPTIC NUCLEUS, the ANTERIOR HYPOTHALAMIC NUCLEUS, and the SUPRACHIASMATIC NUCLEUS.

Hypothalamus, Middle - Middle portion of the hypothalamus containing the arcuate, dorsomedial, ventromedial nuclei, the TUBER CINEREUM and the PITUITARY GLAND.

Hypothalamus, Posterior - The part of the hypothalamus posterior to the middle region consisting of several nuclei including the medial maxillary nucleus, lateral mammillary nucleus, and posterior hypothalamic nucleus (posterior hypothalamic area). The posterior hypothalamic area is concerned with control of sympathetic responses and is sensitive to conditions of decreasing temperature and controls the mechanisms for the conservation and increased production of heat.

Ichthyosis, X-Linked - Chronic form of ichthyosis that is inherited as a sex-linked recessive trait carried on the X-chromosome and transmitted to the male offspring. It is characterized by severe scaling, especially on the extremities, and is associated with steroid sulfatase deficiency.

Inferior Wall Myocardial Infarction - MYOCARDIAL INFARCTION in which the inferior wall of the heart is involved. It is often caused by occlusion of the right coronary artery.

Insulin Infusion Systems - Portable or implantable devices for infusion of insulin. Includes open-loop systems which may be patient-operated or controlled by a pre-set program and are designed for constant delivery of small quantities of insulin, increased during food ingestion, and closed-loop systems which deliver quantities of insulin automatically based on an electronic glucose sensor.

Internal Hernia - A protrusion of an internal abdominal organ through a hole in an anatomical structure such as a muscle or a membrane. For instance, in paraduodenal hernia the SMALL INTESTINE herniates through an opening in the MESENTERIES. It includes intra-abdominal and diaphragmatic hernias. In abdominal hernia a protrusion occurs through a weak spot in the muscle of the ABDOMINAL WALL.

Intralaminar Thalamic Nuclei - Cell groups within the internal medullary lamina of the THALAMUS. They include a rostral division comprising the paracentral, central lateral, central dorsal, and central medial nuclei, and a caudal division composed of the centromedian and parafascicular nuclei.

Ischium - One of three bones that make up the coxal bone of the pelvic girdle. In tetrapods, it is the part of the pelvis that projects backward on the ventral side, and in primates, it bears the weight of the sitting animal.

Islets of Langerhans - Irregular microscopic structures consisting of cords of endocrine cells that are scattered throughout the PANCREAS among the exocrine acini. Each islet is surrounded by connective tissue fibers and penetrated by a network of capillaries. There are four major cell types. The most abundant beta cells (50-80%) secrete INSULIN. Alpha cells (5-20%) secrete GLUCAGON. PP cells (10-35%) secrete PANCREATIC POLYPEPTIDE. Delta cells (~5%) secrete SOMATOSTATIN.

Jejunal Neoplasms - Tumors or cancer in the JEJUNUM region of the small intestine (INTESTINE, SMALL).

Jejunum - The middle portion of the SMALL INTESTINE, between DUODENUM and ILEUM. It represents about 2/5 of the remaining portion of the small intestine below duodenum.

Lacrimal Apparatus - The tear-forming and tear-conducting system which includes the lacrimal glands, eyelid margins, conjunctival sac, and the tear drainage system.

Lacrimal Duct Obstruction - Interference with the secretion of tears by the lacrimal glands. Obstruction of the LACRIMAL SAC or NASOLACRIMAL DUCT causing acute or chronic inflammation of the lacrimal sac (DACRYOCYSTITIS). It is caused also in infants by failure of the nasolacrimal duct to open into the inferior meatus and occurs about the third week of life. In adults occlusion may occur spontaneously or after injury or nasal disease. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p250)

Leber Congenital Amaurosis - A rare degenerative inherited eye disease that appears at birth or in the first few months of life that results in a loss of vision. Not to be confused with LEBER HEREDITARY OPTIC NEUROPATHY, the disease is thought to be caused by abnormal development of PHOTORECEPTOR CELLS in the RETINA, or by the extremely premature degeneration of retinal cells.

Limbic Encephalitis - A paraneoplastic syndrome marked by degeneration of neurons in the LIMBIC SYSTEM. Clinical features include HALLUCINATIONS, loss of EPISODIC MEMORY; ANOSMIA; AGEUSIA; TEMPORAL LOBE EPILEPSY; DEMENTIA; and affective disturbance (depression). Circulating anti-neuronal antibodies (e.g., anti-Hu; anti-Yo; anti-Ri; and anti-Ma2) and small cell lung carcinomas or testicular carcinoma are frequently associated with this syndrome.

Lumbosacral Plexus - The lumbar and sacral plexuses taken together. The fibers of the lumbosacral plexus originate in the lumbar and upper sacral spinal cord (L1 to S3) and innervate the lower extremities.

Mandible - The largest and strongest bone of the FACE constituting the lower jaw. It supports the lower teeth.

Medicine, Chinese Traditional - A system of traditional medicine which is based on the beliefs and practices of the Chinese culture.

Mediodorsal Thalamic Nucleus - The largest of the medial nuclei of the thalamus. It makes extensive connections with most of the other thalamic nuclei.

Medulloblastoma - A malignant neoplasm that may be classified either as a glioma or as a primitive neuroectodermal tumor of childhood (see NEUROECTODERMAL TUMOR, PRIMITIVE). The tumor occurs most frequently in the first decade of life with the most typical location being the cerebellar vermis. Histologic features include a high degree of cellularity, frequent mitotic figures, and a tendency for the cells to organize into sheets or form rosettes. Medulloblastoma have a high propensity to spread throughout the craniospinal intradural axis. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2060-1)

Meninges - The three membranes that cover the BRAIN and the SPINAL CORD. They are the dura mater, the arachnoid, and the pia mater.

Meningocele - A congenital or acquired protrusion of the meninges, unaccompanied by neural tissue, through a bony defect in the skull or vertebral column.

Mesocolon - The fold of peritoneum by which the COLON is attached to the posterior ABDOMINAL WALL.

Microaneurysm - Aneurysm of the MICROVASCULATURE. Charcot–Bouchard aneurysms are aneurysms of the brain vasculature which is a common cause of CEREBRAL HEMORRHAGE. Retinal microaneurysm is an early diagnostic sign of DIABETIC RETINOPATHY.

Midline Thalamic Nuclei - Small, nonspecific nerve cells scattered in the periventricular GRAY MATTER, separating the medial part of the thalamus from the EPENDYMA of the THIRD VENTRICLE. The group includes the paraventricular nucleus, paratenial nucleus, reuniens nucleus, rhomboidal nucleus, and subfascular nucleus.

Multifocal Choroiditis - A multifocal uveitis syndrome involving the RETINAL PIGMENT EPITHELIUM and capillary layer of the CHOROID. It is characterized by chronic UVEITIS and multiple CHOROID lesions referred to as white dots, blurry vision, floaters, sensitivity to light, blind spots, and eye discomfort.

Myocardial Stunning - Prolonged dysfunction of the myocardium after a brief episode of severe ischemia, with gradual return of contractile activity.

Myocardium - The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.

Myometrium - The smooth muscle coat of the uterus, which forms the main mass of the organ.

Nasolacrimal Duct - A tubular duct that conveys TEARS from the LACRIMAL GLAND to the nose.

Nesidioblastosis - An inherited autosomal recessive syndrome characterized by the disorganized formation of new islets in the PANCREAS and CONGENITAL HYPERINSULINISM. It is due to focal hyperplasia of pancreatic ISLET CELLS budding off from the ductal structures and forming new islets of Langerhans. Mutations in the islet cells involve the potassium channel gene KCNJ11 or the ATP-binding cassette transporter gene ABCC8, both on CHROMOSOME 11.

Neuroectodermal Tumor, Melanotic - A benign, rapidly growing, deeply pigmented tumor of the jaw and occasionally of other sites, consisting of an infiltrating mass of cells arranged in an alveolar pattern, and occurring almost exclusively in infants. Its source of origin is in dispute, the various theories giving rise to its several names. (Dorland, 27th ed)

Nucleus Pulposus - Fibrocartilage inner core of the intervertebral disc. Prolapsed or bulged nucleus pulposus leads to INTERVERTEBRAL DISC DISPLACEMENT while proliferation of cells in the nucleus pulposus is associated with INTERVERTEBRAL DISC DEGENERATION.

Omentum - A double-layered fold of peritoneum that attaches the STOMACH to other organs in the ABDOMINAL CAVITY.

Oral Frenectomy - Surgical procedures to release or remove abnormally short or tightly attached frenum (e.g., LINGUAL FRENUM or LABIAL FRENUM) associated with a pathological condition (e.g., TONGUE TIE and lip tie).

Oropharyngeal Neoplasms - Tumors or cancer of the OROPHARYNX.

Oropharynx - The middle portion of the pharynx that lies posterior to the mouth, inferior to the SOFT PALATE, and superior to the base of the tongue and EPIGLOTTIS. It has a digestive function as food passes from the mouth into the oropharynx before entering ESOPHAGUS.

Palatal Obturators - Appliances that close a cleft or fissure of the palate.

Palate - The structure that forms the roof of the mouth. It consists of the anterior hard palate (PALATE, HARD) and the posterior soft palate (PALATE, SOFT).

Palate, Hard - The anteriorly located rigid section of the PALATE.

Palate, Soft - A movable fold suspended from the posterior border of the hard palate. The uvula hangs from the middle of the lower border.

Pancreas - A nodular organ in the ABDOMEN that contains a mixture of ENDOCRINE GLANDS and EXOCRINE GLANDS. The small endocrine portion consists of the ISLETS OF LANGERHANS secreting a number of hormones into the blood stream. The large exocrine portion (EXOCRINE PANCREAS) is a compound acinar gland that secretes several digestive enzymes into the pancreatic ductal system that empties into the DUODENUM.

Pancreas Divisum - Anatomic variants in PANCREATIC DUCTS characterized by failure of fusion of the ventral and dorsal endodermal buds. Pancreas divisum results in inadequate or no communication between dorsal and ventral ducts. While most cases are asymptomatic, it may be associated with recurrent PANCREATITIS.

Pancreas Transplantation - The transference of a pancreas from one human or animal to another.

Pancreas, Artificial - Devices for simulating the activity of the pancreas. They can be either electromechanical, consisting of a glucose sensor, computer, and insulin pump or bioartificial, consisting of isolated islets of Langerhans in an artificial membrane.

Pancreas, Exocrine - The major component (about 80%) of the PANCREAS composed of acinar functional units of tubular and spherical cells. The acinar cells synthesize and secrete several digestive enzymes such as TRYPSINOGEN; LIPASE; AMYLASE; and RIBONUCLEASE. Secretion from the exocrine pancreas drains into the pancreatic ductal system and empties into the DUODENUM.

Pancreatic Neoplasms - Tumors or cancer of the PANCREAS. Depending on the types of ISLET CELLS present in the tumors, various hormones can be secreted: GLUCAGON from PANCREATIC ALPHA CELLS; INSULIN from PANCREATIC BETA CELLS; and SOMATOSTATIN from the SOMATOSTATIN-SECRETING CELLS. Most are malignant except the insulin-producing tumors (INSULINOMA).

Pancrelipase - A preparation of hog pancreatic enzymes standardized for lipase content.

Papilledema - Swelling of the OPTIC DISK, usually in association with increased intracranial pressure, characterized by hyperemia, blurring of the disk margins, microhemorrhages, blind spot enlargement, and engorgement of retinal veins. Chronic papilledema may cause OPTIC ATROPHY and visual loss. (Miller et al., Clinical Neuro-Ophthalmology, 4th ed, p175)

Papilloma, Choroid Plexus - A usually benign neoplasm that arises from the cuboidal epithelium of the choroid plexus and takes the form of an enlarged CHOROID PLEXUS, which may be associated with oversecretion of CSF. The tumor usually presents in the first decade of life with signs of increased intracranial pressure including HEADACHES; ATAXIA; DIPLOPIA; and alterations of mental status. In children it is most common in the lateral ventricles and in adults it tends to arise in the fourth ventricle. Malignant transformation to choroid plexus carcinomas may rarely occur. (Adams et al., Principles of Neurology, 6th ed, p667; DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2072)

Paraneoplastic Cerebellar Degeneration - Cerebellar degeneration associated with a remote neoplasm. Clinical manifestations include progressive limb and GAIT ATAXIA; DYSARTHRIA; and NYSTAGMUS, PATHOLOGIC. The histologic type of the associated neoplasm is usually carcinoma or lymphoma. Pathologically the cerebellar cortex and subcortical nuclei demonstrate diffuse degenerative changes. Anti-Purkinje cell antibodies (anti-Yo) are found in the serum of approximately 50% of affected individuals. (Adams et al., Principles of Neurology, 6th ed, p686)

Pelvic Floor - Soft tissue formed mainly by the pelvic diaphragm, which is composed of the two levator ani and two coccygeus muscles. The pelvic diaphragm lies just below the pelvic aperture (outlet) and separates the pelvic cavity from the PERINEUM. It extends between the PUBIC BONE anteriorly and the COCCYX posteriorly.

Pentastomida - A subclass of CRUSTACEA comprising the tongue worms which are obligatory parasites of reptiles, birds, and mammals including humans.

Pericardial Fluid - Watery fluid produced in the serous and visceral pericardium surrounding the surface of the HEART.

Pericardium - A conical fibro-serous sac surrounding the HEART and the roots of the great vessels (AORTA; VENAE CAVAE; PULMONARY ARTERY). Pericardium consists of two sacs: the outer fibrous pericardium and the inner serous pericardium. The latter consists of an outer parietal layer facing the fibrous pericardium, and an inner visceral layer (epicardium) resting next to the heart, and a pericardial cavity between these two layers.

Perilipin-3 - A perilipin that localizes to LIPID DROPLETS; CYTOPLASM; ENDOSOMES; and PLASMA MEMBRANE, especially in MACROPHAGES. It functions as a transporter of free fatty acids to lipid droplets to promote their biogenesis and growth. It is also required for the transport of the MANNOSE-6-PHOSPHATE RECEPTOR from endosomes to the TRANS-GOLGI NETWORK. Its structure consists of four helix bundles that interact with the hydrophobic lipid droplet surface.

Perineum - The body region lying between the genital area and the ANUS on the surface of the trunk, and to the shallow compartment lying deep to this area that is inferior to the PELVIC DIAPHRAGM. The surface area is between the VULVA and the anus in the female, and between the SCROTUM and the anus in the male.

Peritoneal Stomata - Natural openings in the subdiaphragmatic lymphatic plexus in the PERITONEUM, delimited by adjacent mesothelial cells. Peritoneal stomata constitute the principal pathways for the drainage of intraperitoneal contents from the PERITONEAL CAVITY to the LYMPHATIC SYSTEM.

Photoreceptor Cells, Vertebrate - Specialized PHOTOTRANSDUCTION neurons in the vertebrates, such as the RETINAL ROD CELLS and the RETINAL CONE CELLS. Non-visual photoreceptor neurons have been reported in the deep brain, the PINEAL GLAND and organs of the circadian system.

Pia Mater - The innermost layer of the three meninges covering the brain and spinal cord. It is the fine vascular membrane that lies under the ARACHNOID and the DURA MATER.

Pituitary Gland - A small, unpaired gland situated in the SELLA TURCICA. It is connected to the HYPOTHALAMUS by a short stalk which is called the INFUNDIBULUM.

Placenta - A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES).

Placenta Accreta - Abnormal placentation in which all or parts of the PLACENTA are attached directly to the MYOMETRIUM due to a complete or partial absence of DECIDUA. It is associated with POSTPARTUM HEMORRHAGE because of the failure of placental separation.

Placenta Diseases - Pathological processes or abnormal functions of the PLACENTA.

Placenta Growth Factor - An angiogenic protein belonging to the Vascular Endothelial Growth Factor family of growth factors originally isolated and cloned from human placental cDNA library. There are four isoforms of PLGF 1-4 which result from alternative splicing. Placenta Growth Factor is secreted as a glycosylated homodimer which acts as a mitogen for endothelial cells, and its expression is markedly upregulated during hypoxia and in tissue inflammation and cancer.

Placenta Previa - Abnormal placentation in which the PLACENTA implants in the lower segment of the UTERUS (the zone of dilation) and may cover part or all of the opening of the CERVIX. It is often associated with serious antepartum bleeding and PREMATURE LABOR.

Placenta, Retained - A placenta that fails to be expelled after BIRTH of the FETUS. A PLACENTA is retained when the UTERUS fails to contract after the delivery of its content, or when the placenta is abnormally attached to the MYOMETRIUM.

Placental Circulation - The circulation of BLOOD, of both the mother and the FETUS, through the PLACENTA.

Placental Extracts - Extracts prepared from placental tissue; they may contain specific but uncharacterized factors or proteins with specific activities.

Placental Function Tests - Methods used for the assessment of placental function.

Placental Hormones - Hormones produced by the placenta include CHORIONIC GONADOTROPIN, and PLACENTAL LACTOGEN as well as steroids (ESTROGENS; PROGESTERONE), and neuropeptide hormones similar to those found in the hypothalamus (HYPOTHALAMIC HORMONES).

Placental Insufficiency - Failure of the PLACENTA to deliver an adequate supply of nutrients and OXYGEN to the FETUS.

Placental Lactogen - A polypeptide hormone of approximately 25 kDa that is produced by the SYNCYTIOTROPHOBLASTS of the PLACENTA, also known as chorionic somatomammotropin. It has both GROWTH HORMONE and PROLACTIN activities on growth, lactation, and luteal steroid production. In women, placental lactogen secretion begins soon after implantation and increases to 1 g or more a day in late pregnancy. Placental lactogen is also an insulin antagonist.

Placentation - The development of the PLACENTA, a highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products between mother and FETUS. The process begins at FERTILIZATION, through the development of CYTOTROPHOBLASTS and SYNCYTIOTROPHOBLASTS, the formation of CHORIONIC VILLI, to the progressive increase in BLOOD VESSELS to support the growing fetus.

Plasminogen Inactivators - Important modulators of the activity of plasminogen activators. The inhibitors belong to the serpin family of proteins and inhibit both the tissue-type and urokinase-type plasminogen activators.

Polymyositis - Diseases characterized by inflammation involving multiple muscles. This may occur as an acute or chronic condition associated with medication toxicity (DRUG TOXICITY); CONNECTIVE TISSUE DISEASES; infections; malignant NEOPLASMS; and other disorders. The term polymyositis is frequently used to refer to a specific clinical entity characterized by subacute or slowly progressing symmetrical weakness primarily affecting the proximal limb and trunk muscles. The illness may occur at any age, but is most frequent in the fourth to sixth decade of life. Weakness of pharyngeal and laryngeal muscles, interstitial lung disease, and inflammation of the myocardium may also occur. Muscle biopsy reveals widespread destruction of segments of muscle fibers and an inflammatory cellular response. (Adams et al., Principles of Neurology, 6th ed, pp1404-9)

Polypoidal Choroidal Vasculopathy - A CHOROID neovascularization characterized by serosanguineous retinal pigment epithelial detachment and leakage of serous exudate sometimes associated with aneurysmal polypoidal lesions.

Porencephaly - Cortical malformations characterized by white matter-lined cleft or cyst associated with ISCHEMIA and hemorrhagic insults. Symptoms include delayed growth and development, HYPOTONIA; SEIZURES; SPASTIC HEMIPLEGIA and MACROCEPHALY; MICROCEPHALY; or HYDROCEPHALUS. Mutations in the genes encoding COLLAGEN TYPE IV are associated with familial types.

Posterior Thalamic Nuclei - A transitional diencephalic zone of the thalamus consisting of complex and varied cells lying caudal to the VENTRAL POSTEROLATERAL NUCLEUS, medial to the rostral part of the PULVINAR, and dorsal to the MEDIAL GENICULATE BODY. It contains the limitans, posterior, suprageniculate, and submedial nuclei.

Pregnancy Proteins - Proteins produced by organs of the mother or the PLACENTA during PREGNANCY. These proteins may be pregnancy-specific (present only during pregnancy) or pregnancy-associated (present during pregnancy or under other conditions such as hormone therapy or certain malignancies.)

Pregnancy Trimester, First - The beginning third of a human PREGNANCY, from the first day of the last normal menstrual period (MENSTRUATION) through the completion of 14 weeks (98 days) of gestation.

Pubic Bone - A bone that forms the lower and anterior part of each side of the hip bone.

Pudendal Nerve - A nerve which originates in the sacral spinal cord (S2 to S4) and innervates the PERINEUM, the external GENITALIA, the external ANAL SPHINCTER and the external urethral sphincter. It has three major branches: the perineal nerve, inferior anal nerves, and the dorsal nerve of penis or clitoris.

Pulvinar - Large mass of nuclei forming the most caudal portion of the THALAMUS and overhanging the GENICULATE BODIES and the dorsolateral surface of the MIDBRAIN. It is divided into four parts: the lateral, medial, inferior, and oral pulvinar nuclei.

Putamen - The largest and most lateral of the BASAL GANGLIA lying between the lateral medullary lamina of the GLOBUS PALLIDUS and the EXTERNAL CAPSULE. It is part of the neostriatum and forms part of the LENTIFORM NUCLEUS along with the GLOBUS PALLIDUS.

Putaminal Hemorrhage - Intracranial bleeding into the PUTAMEN, a BASAL GANGLIA nucleus. This is associated with HYPERTENSION and lipohyalinosis of small blood vessels in the putamen. Clinical manifestations vary with the size of hemorrhage, but include HEMIPARESIS; HEADACHE; and alterations of consciousness.

Pyloric Stenosis - Narrowing of the pyloric canal with varied etiology. A common form is due to muscle hypertrophy (PYLORIC STENOSIS, HYPERTROPHIC) seen in infants.

Pylorus - The region of the STOMACH at the junction with the DUODENUM. It is marked by the thickening of circular muscle layers forming the pyloric sphincter to control the opening and closure of the lumen.

Receptor-Like Protein Tyrosine Phosphatases, Class 3 - A subclass of receptor-like protein tryosine phosphatases that contain a single cytosolic protein tyrosine phosphate domain and multiple extracellular fibronectin III-like domains.

Respiratory Paralysis - Complete or severe weakness of the muscles of respiration. This condition may be associated with MOTOR NEURON DISEASES; PERIPHERAL NERVE DISEASES; NEUROMUSCULAR JUNCTION DISEASES; SPINAL CORD DISEASES; injury to the PHRENIC NERVE; and other disorders.

Retina - The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.

Retinal Arterial Macroaneurysm - An acquired dilation of the retinal artery often associated with systemic HYPERTENSION.

Retinal Artery - Central retinal artery and its branches. It arises from the ophthalmic artery, pierces the optic nerve and runs through its center, enters the eye through the porus opticus and branches to supply the retina.

Retinal Artery Occlusion - Sudden ISCHEMIA in the RETINA due to blocked blood flow through the CENTRAL RETINAL ARTERY or its branches leading to sudden complete or partial loss of vision, respectively, in the eye.

Retinal Bipolar Cells - INTERNEURONS of the vertebrate RETINA containing two processes. They receive inputs from the RETINAL PHOTORECEPTOR CELLS and send outputs to the RETINAL GANGLION CELLS. The bipolar cells also make lateral connections in the retina with the RETINAL HORIZONTAL CELLS and with the AMACRINE CELLS.

Retinal Cone Photoreceptor Cells - Photosensitive afferent neurons located primarily within the FOVEA CENTRALIS of the MACULA LUTEA. There are three major types of cone cells (red, blue, and green) whose photopigments have different spectral sensitivity curves. Retinal cone cells operate in daylight vision (at photopic intensities) providing color recognition and central visual acuity.

Retinal Degeneration - A retrogressive pathological change in the retina, focal or generalized, caused by genetic defects, inflammation, trauma, vascular disease, or aging. Degeneration affecting predominantly the macula lutea of the retina is MACULAR DEGENERATION. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p304)

Retinal Dehydrogenase - A metalloflavoprotein enzyme involved the metabolism of VITAMIN A, this enzyme catalyzes the oxidation of RETINAL to RETINOIC ACID, using both NAD+ and FAD coenzymes. It also acts on both the 11-trans- and 13-cis-forms of RETINAL.

Retinal Detachment - Separation of the inner layers of the retina (neural retina) from the pigment epithelium. Retinal detachment occurs more commonly in men than in women, in eyes with degenerative myopia, in aging and in aphakia. It may occur after an uncomplicated cataract extraction, but it is seen more often if vitreous humor has been lost during surgery. (Dorland, 27th ed; Newell, Ophthalmology: Principles and Concepts, 7th ed, p310-12).

Retinal Diseases - Diseases involving the RETINA.

Retinal Drusen - Colloid or hyaline bodies lying beneath the retinal pigment epithelium. They may occur either secondary to changes in the choroid that affect the pigment epithelium or as an autosomal dominant disorder of the retinal pigment epithelium.

Retinal Dysplasia - Congenital, often bilateral, retinal abnormality characterized by the arrangement of outer nuclear retinal cells in a palisading or radiating pattern surrounding a central ocular space. This disorder is sometimes hereditary.

Retinal Dystrophies - A group of disorders involving predominantly the posterior portion of the ocular fundus, due to degeneration in the sensory layer of the RETINA; RETINAL PIGMENT EPITHELIUM; BRUCH MEMBRANE; CHOROID; or a combination of these tissues.

Retinal Ganglion Cells - Neurons of the innermost layer of the retina, the internal plexiform layer. They are of variable sizes and shapes, and their axons project via the OPTIC NERVE to the brain. A small subset of these cells act as photoreceptors with projections to the SUPRACHIASMATIC NUCLEUS, the center for regulating CIRCADIAN RHYTHM.

Retinal Hemorrhage - Bleeding from the vessels of the retina.

Retinal Horizontal Cells - NEURONS in the inner nuclear layer of the RETINA that synapse with both the RETINAL PHOTORECEPTOR CELLS and the RETINAL BIPOLAR CELLS, as well as other horizontal cells. The horizontal cells modulate the sensory signal.

Retinal Necrosis Syndrome, Acute - Mild to fulminant necrotizing vaso-occlusive retinitis associated with a high incidence of retinal detachment and poor vision outcome.

Retinal Neoplasms - Tumors or cancer of the RETINA.

Retinal Neovascularization - Formation of new blood vessels originating from the retinal veins and extending along the inner (vitreal) surface of the retina.

Retinal Neurons - Nerve cells of the RETINA in the pathway of transmitting light signals to the CENTRAL NERVOUS SYSTEM. They include the outer layer of PHOTORECEPTOR CELLS, the intermediate layer of RETINAL BIPOLAR CELLS and AMACRINE CELLS, and the internal layer of RETINAL GANGLION CELLS.

Retinal Perforations - Perforations through the whole thickness of the retina including the macula as the result of inflammation, trauma, degeneration, etc. The concept includes retinal breaks, tears, dialyses, and holes.

Retinal Photoreceptor Cell Inner Segment - The inner portion of a retinal rod or a cone photoreceptor cell, situated between the PHOTORECEPTOR CONNECTING CILIUM and the synapse with the adjacent neurons (RETINAL BIPOLAR CELLS; RETINAL HORIZONTAL CELLS). The inner segment contains the cell body, the nucleus, the mitochondria, and apparatus for protein synthesis.

Retinal Photoreceptor Cell Outer Segment - The light sensitive outer portion of a retinal rod or a cone photoreceptor cell. The outer segment contains a stack of disk membranes laden with photoreceptive pigments (RETINAL PIGMENTS). The outer segment is connected to the inner segment by a PHOTORECEPTOR CONNECTING CILIUM.

Retinal Pigment Epithelium - The single layer of pigment-containing epithelial cells in the RETINA, situated closely to the tips (outer segments) of the RETINAL PHOTORECEPTOR CELLS. These epithelial cells are macroglia that perform essential functions for the photoreceptor cells, such as in nutrient transport, phagocytosis of the shed photoreceptor membranes, and ensuring retinal attachment.

Retinal Pigments - Photosensitive protein complexes of varied light absorption properties which are expressed in the PHOTORECEPTOR CELLS. They are OPSINS conjugated with VITAMIN A-based chromophores. Chromophores capture photons of light, leading to the activation of opsins and a biochemical cascade that ultimately excites the photoreceptor cells.

Retinal Rod Photoreceptor Cells - Photosensitive afferent neurons located in the peripheral retina, with their density increases radially away from the FOVEA CENTRALIS. Being much more sensitive to light than the RETINAL CONE CELLS, the rod cells are responsible for twilight vision (at scotopic intensities) as well as peripheral vision, but provide no color discrimination.

Retinal Telangiectasis - A group of rare, idiopathic, congenital retinal vascular anomalies affecting the retinal capillaries. It is characterized by dilation and tortuosity of retinal vessels and formation of multiple aneurysms, with different degrees of leakage and exudates emanating from the blood vessels.

Retinal Vasculitis - Inflammation of the retinal vasculature with various causes including infectious disease; LUPUS ERYTHEMATOSUS, SYSTEMIC; MULTIPLE SCLEROSIS; BEHCET SYNDROME; and CHORIORETINITIS.

Retinal Vein - Central retinal vein and its tributaries. It runs a short course within the optic nerve and then leaves and empties into the superior ophthalmic vein or cavernous sinus.

Retinal Vein Occlusion - Blockage of the RETINAL VEIN. Those at high risk for this condition include patients with HYPERTENSION; DIABETES MELLITUS; ATHEROSCLEROSIS; and other CARDIOVASCULAR DISEASES.

Retinal Vessels - The blood vessels which supply and drain the RETINA.

Retinaldehyde - A diterpene derived from the carotenoid VITAMIN A which functions as the active component of the visual cycle. It is the prosthetic group of RHODOPSIN (i.e., covalently bonded to ROD OPSIN as 11-cis-retinal). When stimulated by visible light, rhodopsin transforms this cis-isomer of retinal to the trans-isomer (11-trans-retinal). This transformation straightens-out the bend of the retinal molecule and causes a change in the shape of rhodopsin triggering the visual process. A series of energy-requiring enzyme-catalyzed reactions convert the 11-trans-retinal back to the cis-isomer.

Retinoblastoma - A malignant tumor arising from the nuclear layer of the retina that is the most common primary tumor of the eye in children. The tumor tends to occur in early childhood or infancy and may be present at birth. The majority are sporadic, but the condition may be transmitted as an autosomal dominant trait. Histologic features include dense cellularity, small round polygonal cells, and areas of calcification and necrosis. An abnormal pupil reflex (leukokoria); NYSTAGMUS, PATHOLOGIC; STRABISMUS; and visual loss represent common clinical characteristics of this condition. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2104)

S100 Calcium-Binding Protein A4 - An S100 protein characterized by four helix bundles that form N- and C-terminal EF HAND MOTIFS. It functions as a homodimer and interacts with both intracellular and extracellular signaling proteins. Aberrant S100A4 activity is associated with NEOPLASM METASTASIS; FIBROSIS; and RHEUMATOID ARTHRITIS.

Schlemm's Canal - A circular vascular-like structure in the anterior chamber of the eye bounded anterolaterally by the internal scleral sulcus and posteriorly by the trabecular meshwork. It is a part of a pathway where the AQUEOUS HUMOR from the ANTERIOR CHAMBER of the eye passes through the TRABECULAR MESHWORK, drains into the lumen of Schlemm’s canal, and subsequently returns to blood circulation into the veins of the SCLERA.

Sciatic Nerve - A nerve which originates in the lumbar and sacral spinal cord (L4 to S3) and supplies motor and sensory innervation to the lower extremity. The sciatic nerve, which is the main continuation of the sacral plexus, is the largest nerve in the body. It has two major branches, the TIBIAL NERVE and the PERONEAL NERVE.

Sciatic Neuropathy - Disease or damage involving the SCIATIC NERVE, which divides into the PERONEAL NERVE and TIBIAL NERVE (see also PERONEAL NEUROPATHIES and TIBIAL NEUROPATHY). Clinical manifestations may include SCIATICA or pain localized to the hip, PARESIS or PARALYSIS of posterior thigh muscles and muscles innervated by the peroneal and tibial nerves, and sensory loss involving the lateral and posterior thigh, posterior and lateral leg, and sole of the foot. The sciatic nerve may be affected by trauma; ISCHEMIA; COLLAGEN DISEASES; and other conditions. (From Adams et al., Principles of Neurology, 6th ed, p1363)

Sclera - The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. It receives the tendons of insertion of the extraocular muscles and at the corneoscleral junction contains the CANAL OF SCHLEMM. (From Cline et al., Dictionary of Visual Science, 4th ed)

Scleral Buckling - An operation for retinal detachment which reduces the size of the globe by indenting the sclera so that it approximates the retina.

Scleral Diseases - General disorders of the sclera or white of the eye. They may include anatomic, embryologic, degenerative, or pigmentation defects.

Sella Turcica - A bony prominence situated on the upper surface of the body of the sphenoid bone. It houses the PITUITARY GLAND.

Shwachman-Diamond Syndrome - An inherited syndrome characterized by EXOCRINE PANCREATIC INSUFFICIENCY; hematologic abnormalities (e.g., bone marrow hypoplasia), and skeletal abnormalities (e.g., metaphyseal chondroplasia). GERMLINE MUTATIONS in the SBDS gene are associated with Shwachman-Diamond Syndrome.

Spasm - An involuntary contraction of a muscle or group of muscles. Spasms may involve SKELETAL MUSCLE or SMOOTH MUSCLE.

Spermatic Cord - Either of a pair of tubular structures formed by DUCTUS DEFERENS; ARTERIES; VEINS; LYMPHATIC VESSELS; and nerves. The spermatic cord extends from the deep inguinal ring through the INGUINAL CANAL to the TESTIS in the SCROTUM.

Spermatic Cord Torsion - The twisting of the SPERMATIC CORD due to an anatomical abnormality that left the TESTIS mobile and dangling in the SCROTUM. The initial effect of testicular torsion is obstruction of venous return. Depending on the duration and degree of cord rotation, testicular symptoms range from EDEMA to interrupted arterial flow and testicular pain. If blood flow to testis is absent for 4 to 6 h, SPERMATOGENESIS may be permanently lost.

Sterilization Reversal - Procedures to reverse the effect of REPRODUCTIVE STERILIZATION and to regain fertility. Reversal procedures include those used to restore the flow in the FALLOPIAN TUBE or the VAS DEFERENS.

Sternum - A long, narrow, and flat bone commonly known as BREASTBONE occurring in the midsection of the anterior thoracic segment or chest region, which stabilizes the rib cage and serves as the point of origin for several muscles that move the arms, head, and neck.

Stomach - An organ of digestion situated in the left upper quadrant of the abdomen between the termination of the ESOPHAGUS and the beginning of the DUODENUM.

Stomach Diseases - Pathological processes involving the STOMACH.

Stomach Neoplasms - Tumors or cancer of the STOMACH.

Stomach Rupture - Bursting of the STOMACH.

Stomach Ulcer - Ulceration of the GASTRIC MUCOSA due to contact with GASTRIC JUICE. It is often associated with HELICOBACTER PYLORI infection or consumption of nonsteroidal anti-inflammatory drugs (NSAIDS).

Stomach Volvulus - Twisting of the STOMACH that may result in gastric ISCHEMIA and GASTRIC OUTLET OBSTRUCTION. It is often associated with DIAPHRAGMATIC HERNIA.

Stomach, Avian - A component of the digestive system of birds which consists of the GIZZARD and PROVENTRICULUS.

Stomach, Ruminant - A component of the DIGESTIVE SYSTEM of RUMINANTS which consists of the ABOMASUM; OMASUM; RETICULUM; and RUMEN.

Submandibular Gland - One of two salivary glands in the neck, located in the space bound by the two bellies of the digastric muscle and the angle of the mandible. It discharges through the submandibular duct. The secretory units are predominantly serous although a few mucous alveoli, some with serous demilunes, occur. (Stedman, 25th ed)

Submandibular Gland Diseases - Diseases involving the SUBMANDIBULAR GLAND.

Submandibular Gland Neoplasms - New abnormal growth of tissue in the SUBMANDIBULAR GLAND.

Supraoptic Nucleus - Hypothalamic nucleus overlying the beginning of the OPTIC TRACT.

Thalamus - Paired bodies containing mostly GRAY MATTER and forming part of the lateral wall of the THIRD VENTRICLE of the brain.

Thymoma - A neoplasm originating from thymic tissue, usually benign, and frequently encapsulated. Although it is occasionally invasive, metastases are extremely rare. It consists of any type of thymic epithelial cell as well as lymphocytes that are usually abundant. Malignant lymphomas that involve the thymus, e.g., lymphosarcoma, Hodgkin's disease (previously termed granulomatous thymoma), should not be regarded as thymoma. (From Stedman, 25th ed)

Tongue - A muscular organ in the mouth that is covered with pink tissue called mucosa, tiny bumps called papillae, and thousands of taste buds. The tongue is anchored to the mouth and is vital for chewing, swallowing, and for speech.

Tongue Diseases - Diseases involving the TONGUE.

Tongue Habits - Acquired responses regularly manifested by tongue movement or positioning.

Tongue Neoplasms - Tumors or cancer of the TONGUE.

Tongue, Fissured - The occurrence of of breaks or slits in the tissue of the dorsal surface of the TONGUE.

Tongue, Hairy - A benign condition of the tongue characterized by hypertrophy of the filiform papillae that give the dorsum of the tongue a furry appearance. The color of the elongated papillae varies from yellowish white to brown or black, depending upon staining by substances such as tobacco, food, or drugs. (Dorland, 27th ed)

Trophoblastic Tumor, Placental Site - An uncommon variant of CHORIOCARCINOMA. It is composed almost entirely of mononuclear cytotrophoblasts (TROPHOBLASTS). Because its secretion of hCG (CHORIONIC GONADOTROPIN) is low, a large tumor may develop before the hCG can be detected.

Umbilical Cord Clamping - Method of placing clamps on the UMBILICAL CORD before cutting after birth.

Urachus - An embryonic structure originating from the ALLANTOIS. It is a canal connecting the fetal URINARY BLADDER and the UMBILICUS. It is normally converted into a fibrous cord postnatally. When the canal fails to be filled and remains open (patent urachus), urine leaks through the umbilicus.

Vas Deferens - The excretory duct of the testes that carries SPERMATOZOA. It rises from the SCROTUM and joins the SEMINAL VESICLES to form the ejaculatory duct.

Ventral Thalamic Nuclei - A large group of nuclei lying between the internal medullary lamina and the INTERNAL CAPSULE. It includes the ventral anterior, ventral lateral, and ventral posterior nuclei.

Vision Disparity - The difference between two images on the retina when looking at a visual stimulus. This occurs since the two retinas do not have the same view of the stimulus because of the location of our eyes. Thus the left eye does not get exactly the same view as the right eye.

Visual Prosthesis - Artificial device such as an externally-worn camera attached to a stimulator on the RETINA, OPTIC NERVE, or VISUAL CORTEX, intended to restore or amplify vision.

White Dot Syndromes - A group of idiopathic multifocal posterior uveitis syndromes involving the CHOROID; RETINAL PIGMENT EPITHELIUM; and RETINA. They are characterized by multiple lesions of hypoautofluorescent dots in the FUNDUS OCULI and reduced VISUAL ACUITY. Several entities including BIRDSHOT CHORIORETINOPATHY are HLA-A ANTIGENS serotype A29 positive.

Instructional Notations

Includes

This note appears immediately under a three character code title to further define, or give examples of, the content of the category.

• 'growth' NOS
• neoplasm NOS
• new growth NOS
• tumor NOS

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

• neoplasms of uncertain behavior D37 D44 D48

• Category D49 classifies by site neoplasms of unspecified morphology and behavior. The term 'mass', unless otherwise stated, is not to be regarded as a neoplastic growth.