MedGen

Retinoblastoma is a malignant tumor of the developing retina that occurs in children, usually before age five years. Retinoblastoma develops from cells that have cancer-predisposing variants in both copies of RB1. Retinoblastoma may be unifocal or multifocal. About 60% of affected individuals have unilateral retinoblastoma with a mean age of diagnosis of 24 months; about 40% have bilateral retinoblastoma with a mean age of diagnosis of 15 months. Heritable retinoblastoma is an autosomal dominant susceptibility for retinoblastoma. Individuals with heritable retinoblastoma are also at increased risk of developing non-ocular tumors. [from GeneReviews]

An inherited malignant tumor that originates in the nuclear layer of the retina. A predisposition to retinoblastoma has been associated with 13q14 cytogenetic abnormalities affecting the RB1 gene. Patients with the inherited form appear to be at increased risk for secondary non-ocular malignancies such as osteosarcoma, malignant fibrous histiocytoma, and fibrosarcoma. [from NCI]

A neuroblastoma arising from the retina. [from NCI]

Oligoastrocytoma is a type of low-grade glioma with a mixed astrocytoma and oligodendroglioma histology, manifesting with headaches, speech and motor problems, seizures and, in some, subarachnoid haemorrhage. [from ORDO]

A tumor (abnormal growth of tissue) of the retina. [from HPO]

A rare variant of diffuse astrocytoma. It is predominantly composed of neoplastic astrocytes showing a small cell body with few, flaccid processes with a low content of glial filaments and scant GFAP expression. This lesion is not well defined and is considered by some authors as an occasional histopathological feature rather than a reproducibly identifiable variant. When occurring in children, this neoplasm may be difficult to separate from pilocytic juvenile astrocytoma. (Adapted from WHO) [from NCI]

Glioblastomas are malignant astrocytic tumors (grade IV according to the WHO classification). [from ORDO]

Transmission of gene defects or chromosomal aberrations/abnormalities which are expressed in extreme variation in the structure or function of the eye. These may be evident at birth, but may be manifested later with progression of the disorder. [from MeSH]

A tumor (abnormal growth of tissue) of the eye. [from HPO]

Astrocytoma is a neoplasm of the central nervous system derived from astrocytes. Astrocytes are a type of glial cell, and thus astrocytoma is a subtype of glioma. [from HPO]

A molecular subtype of glioblastoma that is associated with younger age at presentation and is characterized by p53 mutations and PDGFRa amplifications. [from NCI]