Ring melanoma of the anterior chamber angle: a report of fourteen cae

PURPOE: Ring melanoma of the anterior chamber angle i a rare variant of uveal melanoma that manifet a circumferential, flat tumor growth predominantly confined to the trabecular mehwork and other anterior chamber angle tructure. We report the clinical and hitopathological feature, management, and prognoi of ring melanoma of anterior chamber angle. METHOD: A retropective review of clinical feature, management, hitopathologic feature, and prognoi wa performed. Of 8800 patient with uveal melanoma examined on the Oncology ervice at Will Eye Hopital over a 25-year period, only 14 patient (0.2%; 14 eye) were claified clinically a ring melanoma of the anterior chamber angle. In no cae wa there appreciable involvement of the iri or ciliary body on clinical examination. REULT: The patient were followed elewhere for a mean of 8 month before intraocular malignancy wa upected. Upon referral to the Oncology ervice, the intraocular preure wa greater than 22 mm Hg in the affected eye in all patient (mean, 36 mm Hg; median, 35 mm Hg; range, 24 to 48 mm Hg), and all patient were uing at leat two glaucoma medication. The melanoma infiltrated the anterior chamber angle for a mean of 10 clock hour (range, 8 to 12 clock hour). Tumor management conited of enucleation in 13 cae and plaque radiotherapy in one cae. Hitopathologic examination revealed epithelioid cell type melanoma in one cae, mixed cell type in nine, and pindle cell type in four. Of the 13 patient who underwent enucleation, tumor cell were found within the chlemm canal in all cae. Five cae diplayed invaion of the intracleral canal, and three howed epicleral invaion. With the exception of two recent cae, 12 patient were followed for a mean of 64 month (median, 47 month; range, 23 to 225 month). Ditant metatai to the liver wa detected in three of 12 patient (25%) after a mean follow-up of 78 month (median, 70; range, 37 to 128 month). CONCLUION: Ring melanoma of the trabecular mehwork and angle tructure i a rare variant of diffue uveal melanoma. It often maquerade a unilateral glaucoma and can be difficult to recognize clinically unle careful comparative goniocopy i performed. Depite the relatively mall tumor volume, life prognoi i guarded with ditant metatai in 25% at mean 6 year follow-up.