Neoplasm of uncertain behavior of other and unspecified sites (D48)

Browse all the diagnosis codes used for neoplasm of uncertain behavior of other and unspecified sites (d48). 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

Angiolymphoid Hyperplasia with Eosinophilia - Solitary or multiple benign cutaneous nodules comprised of immature and mature vascular structures intermingled with endothelial cells and a varied infiltrate of eosinophils, histiocytes, lymphocytes, and mast cells.

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

APUD Cells - Cells with the capacity to take up and decarboxylate the amine precursors DIHYDROXYPHENYLALANINE or 5-HYDROXYTRYPTOPHAN. This is a property of endocrine cells of neural and non-neural origin. APUDOMA is a general term collectively applied to tumors associated with APUD cells.

Apudoma - A general term collectively applied to tumors associated with the APUD CELLS series, irrespective of their specific identification.

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.

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.

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)

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

Chondromatosis - Multiple formation of chondromas. (Dorland, 27th ed)

Chondromatosis, Synovial - Rare, benign, chronic, progressive metaplasia in which cartilage is formed in the synovial membranes of joints, tendon sheaths, or bursae. Some of the metaplastic foci can become detached producing loose bodies. When the loose bodies undergo secondary calcification, the condition is called synovial osteochondromatosis.

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.

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.

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.

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.

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.

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.

Ganglioglioma - Rare indolent tumors comprised of neoplastic glial and neuronal cells which occur primarily in children and young adults. Benign lesions tend to be associated with long survival unless the tumor degenerates into a histologically malignant form. They tend to occur in the optic nerve and white matter of the brain and spinal cord.

Giant Cell Tumor of Bone - A bone tumor composed of cellular spindle-cell stroma containing scattered multinucleated giant cells resembling osteoclasts. The tumors range from benign to frankly malignant lesions. The tumor occurs most frequently in an end of a long tubular bone in young adults. (From Dorland, 27th ed; Stedman, 25th ed)

Hemangioblastoma - A benign tumor of the nervous system that may occur sporadically or in association with VON HIPPEL-LINDAU DISEASE. It accounts for approximately 2% of intracranial tumors, arising most frequently in the cerebellar hemispheres and vermis. Histologically, the tumors are composed of multiple capillary and sinusoidal channels lined with endothelial cells and clusters of lipid-laden pseudoxanthoma cells. Usually solitary, these tumors can be multiple and may also occur in the brain stem, spinal cord, retina, and supratentorial compartment. Cerebellar hemangioblastomas usually present in the third decade with INTRACRANIAL HYPERTENSION, and ataxia. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2071-2)

Hemangioendothelioma - A neoplasm derived from blood vessels, characterized by numerous prominent endothelial cells that occur singly, in aggregates, and as the lining of congeries of vascular tubes or channels. Hemangioendotheliomas are relatively rare and are of intermediate malignancy (between benign hemangiomas and conventional angiosarcomas). They affect men and women about equally and rarely develop in childhood. (From Stedman, 25th ed; Holland et al., Cancer Medicine, 3d ed, p1866)

Hemangioendothelioma, Epithelioid - A tumor of medium-to-large veins, composed of plump-to-spindled endothelial cells that bulge into vascular spaces in a tombstone-like fashion. These tumors are thought to have borderline aggression, where one-third develop local recurrences, but only rarely metastasize. It is unclear whether the epithelioid hemangioendothelioma is truly neoplastic or an exuberant tissue reaction, nor is it clear if this is equivalent to Kimura's disease (see ANGIOLYMPHOID HYPERPLASIA WITH EOSINOPHILIA). (Segen, Dictionary of Modern Medicine, 1992)

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 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)

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.

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.

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.

Leiomyoma - A benign tumor derived from smooth muscle tissue, also known as a fibroid tumor. They rarely occur outside of the UTERUS and the GASTROINTESTINAL TRACT but can occur in the SKIN and SUBCUTANEOUS TISSUE, probably arising from the smooth muscle of small blood vessels in these tissues.

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.

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.

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.

Myofibromatosis - A condition characterized by multiple formations of myofibromas (LEIOMYOMA).

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

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.

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)

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.

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.

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.

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.

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

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)

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.

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

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.

Teratoma - A true neoplasm composed of a number of different types of tissue, none of which is native to the area in which it occurs. It is composed of tissues that are derived from three germinal layers, the endoderm, mesoderm, and ectoderm. They are classified histologically as mature (benign) or immature (malignant). (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1642)

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

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.

• neurofibromatosis nonmalignant Q85.0