Iris naevi are common, making up to 63% of melanocytic iris tumours found in adults1. In contrast, iris melanomas are rare, making up only 2-8% of all uveal melanomas2. Most are believed to arise from iris naevi, with an estimated transformation rate of 4% over 10 years, and 11% over 20 years3. Iris melanoma typically display two patterns of growth, circumscribed or diffuse. Progress tends to be slow - either locally along the surface of the iris, locally into the anterior chamber or invading into the ciliary body4. Metastases of iris melanoma occurs in up to 10% of cases over 20 years and are influenced by factors such as the cytology of the tumour, increased age of the patient and angle involvement. This renders the distinction between naevus and melanoma, and then the different histological subtypes, clinically important.
Sign up to keep reading
Create a free Member account at NZ Optics to read this article and more.
- Read all Member articles
- Full digital magazine archive
