Iris melanoma seeding through a trabeculectomy site.

A 59-year-old man who had previously undergone a trabeculectomy in his right eye was examined because of an enlarging pigmented lesion of the inferior portion of the iris. A fine-needle aspiration biopsy of aqueous fluid revealed spindle cells and epithelioid malignant melanoma cells. The eye was enucleated, and subsequent histopathologic examination demonstrated a mixed spindle cell and epithelioid cell melanoma of the inferior portion of the iris with seeding of melanoma cells into the conjunctival filtering bleb via the trabeculectomy site. This case illustrates the usefulness of fine-needle aspiration biopsy in the evaluation of pigmented iris lesions and illustrates that iris melanoma can seed through a trabeculectomy site.