Skin tests with soluble melanoma antigens in patients with choroidal tumors

The cutaneous delayed hypersensitivity reactions with a soluble melanoma antigen in patients with choroidal mass lesions were studied. Ninety percent of patients with pathologically documented choroidal melanomas had positive melanoma antigen skin test responses. There did not appear to be any difference in the histologic appearance of the tumor nor in the disease status of those patients with positive versus those patients with negative skin test reactions. A 21% instance of false-positive responses with this partially purified soluble melanoma antigen in patients with simulating lesions was observed. The cause for this reactivity is unclear; however, from previous work tissue-associated antigens or fetal antigens are the most probable etiologies for the false-positive melanoma antigen skin tests observed. Further purification of the melanoma-associated antigen preparation may increase the specificity. The results of this study would mitigate against the use of this soluble melanoma antigen skin test in the primary evaluation of patients with pigmented choroidal mass lesions. Currently, the assay is being tested to ascertain its correlation with prognosis and as a means of monitoring immunotherapy.