Corneal infiltration and xanthoma formation in mycosis fungoides

PURPOSE: To report a case of corneal infiltration and xanthoma formation in mycosis fungoides (cutaneous T-cell lymphoma). OBSERVATIONS: A middle aged Japanese man with mycosis fungoides (MF) involving the face was referred to Ophthalmology for evaluation of unilateral, painless conjunctival injection. Biopsy of the conjunctiva revealed a malignant T cell population consistent with MF tumor invasion. Years later, he returned following several episodes of infectious keratitis with a painless, yellow, rapidly forming mass in the left eye over two weeks. Corneal biopsy showed foamy histiocytes and positive staining for CD68, and a diagnosis of corneal xanthoma was made. CONCLUSIONS AND IMPORTANCE: Severe ocular surface disease can rarely occur in MF by direct invasion of tumor cells. Corneal infiltration and xanthoma development may be avoidable by careful monitoring for infectious keratitis in patients with conjunctival involvement, as in our case.