INITIAL MANAGEMENT AND FOLLOW-UP OF MELANOCYTIC IRIS TUMORS

Purposes: To identify clinical variables prognostic for prompt excisio n of melanocytic iris tumors and to determine the clinical factors pre dictive of enlargement of those tumors managed initially by observatio n. Methods: A retrospective study of 285 patients evaluated in a refer ral center over a 15-year interval (1972-1986). Results: Thirty-six le sions were excised promptly, whereas 249 were observed. Eighty-nine pe rcent of the 36 promptly excised tumors were malignant melanomas on hi stopathologic examination. Five clinical variables were associated str ongly with prompt excision: largest basal tumor diameter greater than 3 mm; presence of pigment dispersion; prominent tumor vascularity; ele vated 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. Conclusions: Most melanocyti c 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 pat ients. Clinical features of the iris lesion appear to enable clinician s to differentiate reasonably well between probable malignant melanoma s, for which prompt treatment seems appropriate, and benign nevi, for which observation with periodic follow-up is likely to be the best man agement.