Choroidal melanoma: clinical features, classification, and top 10 pseudomelanomas

To review the current features and classification of choroidal melanoma, and to identify the lesions that clinically simulate choroidal melanoma (pseudomelanoma).

Uveal melanoma is a serious life-threatening intraocular malignancy, most often found in Caucasians (98%) and primarily involving the choroid (90%), ciliary body (7%), or iris (2%). This review will concentrate on choroidal melanoma. At diagnosis, choroidal melanoma usually appears as a pigmented (85%) tumor underlying the retina with a median basal dimension of 11 mm and a mean thickness of 4.5 mm. The American Joint Committee on Cancer classification allows for categorization and staging of melanoma. Following ocular therapy, adjuvant systemic therapy is provided for patients with high-risk melanoma who demonstrate alterations in chromosomes 3, 6, and 8 or those with class 2 on gene-expression profiling, detected by needle biopsy or solid tumor biopsy. The prognosis of choroidal melanoma depends most importantly on the genetic alterations and tumor size. Every millimeter increase in thickness leads to a 5% increased risk for metastasis. The leading conditions that simulate choroidal melanoma include choroidal nevus, peripheral exudative hemorrhagic chorioretinopathy, congenital hypertrophy of the retinal pigment epithelium (RPE), hemorrhagic RPE detachment, choroidal hemangioma, age-related macular degeneration, RPE hyperplasia, and others. These pseudomelanomas can be differentiated from choroidal melanoma by their unique clinical features.

Choroidal melanoma is a serious malignancy with characteristic features. Early detection and therapy is important. Pseudomelanomas can lead to diagnostic confusion; however, clinical features aid in differentiation.