A malignant melanoma originating within the eye. The tumor originates from the melanocytes in the uvea (which comprises the iris, ciliary body, and choroid).

A malignant melanoma originating within the eye. The tumor originates from the melanocytes in the uvea (which comprises the iris, ciliary body, and choroid).

Malignant melanoma is a neoplasm of pigment-producing cells called melanocytes that occurs most often in the skin, but may also occur in the eyes, ears, gastrointestinal tract, leptomeninges, and oral and genital mucous membranes (summary by Habif, 2010). Genetic Heterogeneity of Susceptibility to Cutaneous Malignant Melanoma The locus for susceptibility to familial cutaneous malignant melanoma-1 (CMM1) has been mapped to chromosome 1p36. Other CMM susceptibility loci include CMM2 (155601), caused by variation in the CDKN2A gene (600160) on chromosome 9p21; CMM3 (609048), caused by variation in the CDK4 gene (123829) on chromosome 12q14; CMM4 (608035), mapped to chromosome 1p22; CMM5 (613099), caused by variation in the MC1R gene (155555) on chromosome 16q24; CMM6 (613972), caused by variation in the XRCC3 gene (600675) on chromosome 14q32; CMM7 (612263), mapped to chromosome 20q11; CMM8 (614456), caused by variation in the MITF gene (156845) on chromosome 3p13; CMM9 (615134), caused by variation in the TERT gene (187270) on chromosome 5p15; and CMM10 (615848), caused by mutation in the POT1 gene (606478) on chromosome 7q31. Somatic mutations causing malignant melanoma have also been identified in several genes, including BRAF (164757), STK11 (602216), PTEN (601728), TRRAP (603015), DCC (120470), GRIN2A (138253), ZNF831, BAP1 (603089), and RASA2 (601589). A large percentage of melanomas (40-60%) carry an activating somatic mutation in the BRAF gene, most often V600E (164757.0001) (Davies et al., 2002; Pollock et al., 2003).

Uveal melanoma (see 155720) is the most common primary intraocular malignancy. Metastases arise in more than 30% of patients, usually to the liver, with a poor prognosis (median survival of 10 months) (summary by Derrien et al., 2021). Somatic monosomy 3, which is an unusual finding in most tumors, is present in approximately 50% of uveal melanomas and is significantly correlated with metastatic disease (summary by Tschentscher et al., 2001). Mutation in the BAP1 gene is known to confer susceptibility to this specific disease. It has been estimated that about 22% of cases of familial uveal melanoma are due to BAP1 mutations. Conversely, uveal melanoma has been reported in about 31% of BAP1 mutation carriers, making it one of the most common manifestations of TPDS1 (Rai et al., 2016; Rai et al., 2017). For a discussion of genetic heterogeneity of susceptibility to uveal melanoma, see UVM1 (606660), caused by mutation in the MBD4 gene (603574) on chromosome 3q21.

Uveal melanoma (see 155720) is the most common primary intraocular malignancy. Metastases arise in more than 30% of patients, usually to the liver, with a poor prognosis (median survival of 10 months). Somatic monosomy 3, which is an unusual finding in most tumors, is present in approximately 50% of uveal melanomas and is significantly correlated with metastatic disease (summary by Tschentscher et al., 2001; Derrien et al., 2021). Treatment with programmed cell death protein-1 inhibitors may result in clinical improvement (Rodrigues et al., 2018).

BAP1 tumor predisposition syndrome (BAP1-TPDS) is associated with an increased risk for a specific skin lesion, BAP1-inactivated melanocytic tumors (BIMT; formerly called atypical Spitz tumors), and the following cancers, in descending order of frequency: uveal (eye) melanoma (UM), malignant mesothelioma (MMe), cutaneous melanoma (CM), renal cell carcinoma (RCC), and basal cell carcinoma (BCC). Hepatocellular carcinoma, cholangiocarcinoma, and meningioma may also be associated with BAP1-TPDS. Affected individuals can have more than one type of primary cancer. In general, the median age of onset of these tumors is younger than in the general population. UM tends to be a more aggressive class 2 tumor with higher risk for metastasis and reduced survival compared to UM occurring in the general population. Due to the limited number of families reported to date, the penetrance, natural history, and frequencies of BAP1-associated tumors are yet to be determined. Other suspected but unconfirmed tumors in BAP1-TPDS include (in alphabetic order): breast cancer, neuroendocrine carcinoma, non-small-cell lung adenocarcinoma, thyroid cancer, and urinary bladder cancer.