Fluorescein angiographic patterns of iris melanocytic tumors.

Iris fluorescein angiography was performed on 23 patients with primary iris melanocytic tumors. Four angiographic patterns were identified, the first three of which were considered to be usually indicative of a benign lesion, based on clinical duration and follow-up, biopsy specimens, and stable patterns on repeated angiography. (1) Eleven moderately to heavily pigmented placoid lesions were angiographically silent, in that they failed to display either a tumor-associated vasculature or diffuse leakage. (2) Seven generally nonpigmented lesions demonstrated a quasi-geometric filigree vascular network, approximating the caliber of the normal radial vasculature. These tumor-associated vessels fluoresced early and in synchrony with the appearance of dye in the radial vasculature from which they probably were derived, but they diffusely and confluently leaked fluorescein in the late phases of the angiogram. (3) Three brown or variably pigmented lesions manifested a mixed angiographic pattern, combining features of groups 1 and 2. (4) The final angiographic pattern was comprised of two pathologically proved mixed spindle-epithelioid cell melanomas, each of which in part or in toto showed diffuse and eventually confluent fluorescence emanating from ill-defined vascular foci. One of these two lesions additionally exhibited a large area that was perfused late by irregular leashes of vessels. The ability to distinguish benign from malignant melanocytic lesions of the iris can be greatly enhanced by iris fluorescein angiography.