False-positive 32P uptake tests

Z. N. Zakov, T. R. Smith and D. M. Albert

Three patients had suspected choroidal melanoma and positive results for radioactive phosphorus (32P) uptake tests, leading to enuclearion in two of the patients. No malignancy was present on histopathologic examination. This experience reemphasizes the need for the ophthalmologist to evaluate the total clinical picture and not to give inappropriate consideration to a "positive" 32P uptake test in deciding for or against enucleation in a suspected choroidal melanoma. The positive 32P uptake test, even with high values, cannot be equated with malignancy, and a variety of nonmalignant lesions may give false-positive results.