Initial management and follow-up of melanocytic iris tumors

To identify clinical variables prognostic for prompt excision of melanocytic iris tumors and to determine the clinical factors predictive of enlargement of those tumors managed initially by observation.

A retrospective study of 285 patients evaluated in a referral center over a 15-year interval (1972-1986).

Thirty-six lesions were excised promptly, whereas 249 were observed. Eighty-nine percent of the 36 promptly excised tumors were malignant melanomas on histopathologic examination. Five clinical variables were associated strongly with prompt excision: largest basal tumor diameter greater than 3 mm; presence of pigment dispersion; prominent tumor vascularity; elevated intraocular pressure; and tumor-related ocular symptoms. In the observed group, the actuarial 5-year rate of lesion enlargement was 6.5% (standard error = 2.1%). Of the ten lesions that enlarged, six were excised and evaluated histopathologically. Five of these six lesions were malignant melanomas on histopathologic study. Largest basal tumor diameter was the only clinical variable strongly predictive of lesion enlargement. Only two patients died of metastatic uveal melanoma, and both were in the promptly treated group.

Most melanocytic iris tumors are benign and do not enlarge appreciably when followed or lead to metastatic disease. However, even prompt locally effective treatment (excision) is insufficient to prevent metastasis in some patients. Clinical features of the iris lesion appear to enable clinicians to differentiate reasonably well between probable malignant melanomas, for which prompt treatment seems appropriate, and benign nevi, for which observation with periodic follow-up is likely to be the best management.