Tapioca melanoma of the iris mimicking a vascular tumour: a clinicopathological correlation.

Although vascular iris processes are usually benign, they may be a clinical manifestation of iris melanoma, and this should be considered in the differential diagnosis. The case is reported of a 20-year-old man with a highly vascularized tapioca melanoma of the left iris without involvement of the anterior chamber angle or ciliary body, but with observed growth tendency. Sector iridectomy was performed 2 months after first examination. In addition, two separate floating tumour nodules were observed in the anterior chamber angle at 6 o'clock and were removed by aspiration. After 1 year follow up, no recurrence of melanoma cells was observed. In tapioca iris melanomas, diagnostic differentiation from congenital, inflammatory, vascular and neoplastic iris processes is required. Careful biomicroscopic examination of the iris in patients with vascular iris tumours may help the ophthalmologist to identify malignant iris melanomas (tapioca type) and plan appropriate surgical treatment.