Adenoma of the pigment epithelium of the ciliary body simulating a malignant melanoma.

A benign adenoma of the pigment epithelium of the ciliary body in a 27-year-old woman simulated a malignant melanoma clinically and resulted in enucleation. The correct diagnosis was not made clinically despite the use of A- and B- scan ultrasonography and the radioactive phosphorus (32P) uptake test, procedures which are usually reliable in differentiating between melanoma and pseudomelanoma. We emphasize the shortcomings of these ancillary tests in differentiating pigment epithelial tumors from malignant melanoma.