Phakomatoses, not elsewhere classified (Q85)
The ICD-10 code Q85 covers a group of rare genetic disorders known as phakomatoses, which include neurofibromatosis, tuberous sclerosis, and related syndromes characterized by abnormal tissue growths affecting the nervous system and skin. These codes specifically classify different types and forms of phakomatoses that do not fall under other separate categories.
The section includes detailed codes such as Q85.00 for unspecified neurofibromatosis, and distinct codes for neurofibromatosis type 1 (Q85.01) and type 2 (Q85.02), conditions notable for symptoms like café au lait spots and schwannomas, respectively. Also included are Q85.1 for tuberous sclerosis, a disorder marked by benign tumors in multiple organs, and Q85.81 for PTEN hamartoma tumor syndrome, also known as Cowden syndrome. Other specific codes address syndromes like Von Hippel-Lindau disease (Q85.83) and various other neurocutaneous syndromes. These codes assist medical coders in accurately recording these complex, multisystem conditions, enabling precise diagnosis and management within healthcare systems.
Congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
Other congenital malformations (Q80-Q89)
Q85 Phakomatoses, not elsewhere classified
Q85.0 Neurofibromatosis (nonmalignant)
- Q85.00 Neurofibromatosis, unspecified
- Q85.01 Neurofibromatosis, type 1
- Q85.02 Neurofibromatosis, type 2
- Q85.03 Schwannomatosis
- Q85.09 Other neurofibromatosis
- Q85.1 Tuberous sclerosis
Q85.8 Other phakomatoses, not elsewhere classified
- Q85.81 PTEN hamartoma tumor syndrome
- Q85.82 Other Cowden syndrome
- Q85.83 Von Hippel-Lindau syndrome
- Q85.89 Other phakomatoses, not elsewhere classified
- Q85.9 Phakomatosis, unspecified
Phakomatoses, not elsewhere classified (Q85)
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.
Clinical Terms
The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.
Angiofibroma
A benign neoplasm of fibrous tissue in which there are numerous small and large, frequently dilated, vascular channels. (Stedman, 25th ed)
Hamartoma
A focal malformation resembling a neoplasm, composed of an overgrowth of mature cells and tissues that normally occur in the affected area.
Hamartoma Syndrome, Multiple
A hereditary disease characterized by multiple ectodermal, mesodermal, and endodermal nevoid and neoplastic anomalies. Facial trichilemmomas and papillomatous papules of the oral mucosa are the most characteristic lesions. Individuals with this syndrome have a high risk of BREAST CANCER; THYROID CANCER; and ENDOMETRIAL CANCER. This syndrome is associated with mutations in the gene for PTEN PHOSPHATASE.
Peutz-Jeghers Syndrome
A hereditary disease caused by autosomal dominant mutations involving CHROMOSOME 19. It is characterized by the presence of INTESTINAL POLYPS, consistently in the JEJUNUM, and mucocutaneous pigmentation with MELANIN spots of the lips, buccal MUCOSA, and digits.
Proteus Syndrome
Hamartoneoplastic malformation syndrome of uncertain etiology characterized by partial GIGANTISM of the hands and/or feet, asymmetry of the limbs, plantar hyperplasia, hemangiomas (HEMANGIOMA), lipomas (LIPOMA), lymphangiomas (LYMPHANGIOMA), epidermal NEVI; MACROCEPHALY; cranial HYPEROSTOSIS, and long-bone overgrowth. Joseph Merrick, the so-called elephant man, apparently suffered from Proteus syndrome and not NEUROFIBROMATOSIS, a disorder with similar characteristics.
Tuberous Sclerosis
Autosomal dominant neurocutaneous syndrome classically characterized by MENTAL RETARDATION; EPILEPSY; and skin lesions (e.g., adenoma sebaceum and hypomelanotic macules). There is, however, considerable heterogeneity in the neurologic manifestations. It is also associated with cortical tuber and HAMARTOMAS formation throughout the body, especially the heart, kidneys, and eyes. Mutations in two loci TSC1 and TSC2 that encode hamartin and tuberin, respectively, are associated with the disease.
Tuberous Sclerosis Complex 1 Protein
An intracellular signaling and tumor suppressor protein that forms a complex with TUBEROUS SCLEROSIS COMPLEX 2 PROTEIN (TSC2) and other signaling factors to negatively regulate MTORC1 signaling and affect cell growth and proliferation. Structurally, it interacts with TSC2 through its N-terminal, which also contains GSK-3BETA phosphorylation sites and a RHO-KINASE activation domain. It also contains a C-terminal coiled-coil domain and ezrin-radixin-moesin (ERM) domain. Mutations in the TSC1 gene are associated with TUBEROUS SCLEROSIS.
Tuberous Sclerosis Complex 2 Protein
An intracellular signaling and tumor suppressor protein that forms a complex with TUBEROUS SCLEROSIS COMPLEX 1 PROTEIN (TSC1) and other signaling factors to negatively regulate MTORC1 and affect cell growth and proliferation. It can also function as GTPASE-ACTIVATING PROTEIN (GAP) for RHEB GTPASE to activate mTORC1 independent of its role in the complex. Structurally, it interacts with TSC1 through its N-terminus, which also contains a leucine zipper and coiled-coil region. It also has multiple phosphorylation sites for different cell signaling kinases, a central coiled-coil region, a C-terminal GAP domain and CALMODULIN binding domain. Mutations in the TSC2 gene are associated with TUBEROUS SCLEROSIS.
