2026 ICD-10-CM Diagnosis Code C79.49Secondary malignant neoplasm of other parts of nervous system

AHRQ’s CCSR groups this code into broader clinical categories.

• 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)

• 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)

• 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.

• 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.

• 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.

• 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)

• Polypoidal Choroidal Vasculopathy

  a choroid neovascularization characterized by serosanguineous retinal pigment epithelial detachment and leakage of serous exudate sometimes associated with aneurysmal polypoidal lesions.

• Uveal Melanoma

  a rare, malignant melanoma arising from the melanocytes of the uvea.

• 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.

• 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.

• Spasm

  an involuntary contraction of a muscle or group of muscles. spasms may involve skeletal muscle or smooth muscle.

• 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.

• Lacrimal Apparatus

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

• 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.

• 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)

• Nasolacrimal Duct

  a tubular duct that conveys tears from the lacrimal gland to the nose.

• 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.

• 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.

• 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.

• 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.

• Foveomacular Retinitis

  a photochemical injury to retina tissues, usually at the retinal pigment epithelium. it is commonly associated with sungazing, eclipse viewing, welding, or using a laser pointer without proper eye protection resulting in subjective visual disturbances (e.g., floaters) and reduced visual acuity.

• 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.

• 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.

• 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)

• 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)

• 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.

• 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.

• 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)

• 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.

• 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.

• 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.

• Metastatic Neuroblastoma

  a neuroblastoma that has metastasized from its original site of growth to another anatomic site.

Anatomical sites in the Table of Neoplasms that reference this code family.

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