Errors in the diagnosis of malignant melanoma of the choroid.

We reviewed our consultations and enucleations for suspected choroidal melanomas from 1954 through 1977. Among 876 eyes enucleated here during that period, 203 contained malignant melanomas; among these were 172 with melanomas of the choroid. Eighteen additional eyes contained melanomas of the anterior uvea. Six melanomas were clinically unsuspected. These unsuspected cases represented 2.6% of the 233 eyes in this series of enucleated eyes that were removed because of painful glaucoma, and 3.2% of the 190 uveal melanomas. Our study included eyes enucleated elsewhere after a clinical diagnosis of malignant melanoma was made here. Six of 224 eyes enucleated for clinically suspected melanoma were found to have mimicking lesions, a misdiagnosis rate of 2.7%. Two additional eyes were misdiagnosed as having simulating lesions before histologic confirmation of malignant melanoma after enucleation elsewhere.