Diffuse malignant melanoma of iris with metastases.

A 66-year-old man had decreased visual acuity in the left eye. Slit-lamp examination showed hyperpigmentation of the periphery of the iris from 2:30 to 9 o'clock. Gonioscopy disclosed an ill-defined mass involving the angle and extending from 5 to 7:30 o'clock with diffuse pigmentation of the meshwork for 360 degrees. A sector iridectomy was performed inferiorly in his left eye. Histopathologic examination disclosed a diffuse malignant melanoma of the iris, mixed cell type. The patient was free of recurrence when examined at 18, 24 and 30 months following surgery. Two years and ten months following the iridectomy, the patient developed multiple metastatic bony lesions and a mass in the liver. Bone marrow aspiration from the sternum and biopsy from the iliac crest, respectively, showed metastatic malignant melanoma. He died shortly thereafter and an autopsy was not performed. The remote possibility of an occult, intraocular tumor such as a ciliary body melanoma or an internally located melanoma cannot be excluded. Assuming that this is indeed an iris melanoma, as our studies indicate, the rarity of this metastatic iris neoplasm is emphasized by noting that only 37 cases of iris melanomas with presumed metastases have been reported in the literature.