Melanocytic nevus with diffuse extension and absolute glaucoma

Background: Ferry et al. (8) showed that 35% of eyes which have been enucle ated because of a clinically suspected malignant iris lesion did not reveal a histologically malignant iris tumor. Patient: A 43-year old male presented with a blind, painful left eye, which has developed over a time period of 6 months. Ophthalmologic examination r evealed the presence of pigmented iris stromal lesions associated with diff use pigmentation of the chamber angle and the development of absolute glauc oma. A diffuse iridociliary malignant melanoma (ring melanoma) was suspecte d and the blind painful eye was enucleated. Histologic examination revealed the presence of a benign melanocytic lesion, i.e. a spindle cell nevus of the iris with surface plaques causing diffuse extension of the chamber angl e, trabecular meshwork, Schlemm's canal, and the ciliary body. Conclusion: The malignant potential of iris lesions may be difficult to ass ess on clinical grounds only. Histologically, benign melanocytic proliferat ion may cause diffuse extension into the ciliary body as well as the chambe r angle leading to an increase in intraocular pressure. In order to reach a final diagnosis a biopsy of the lesion is necessary.