Ring melanoma of the ciliary body: report on twenty-three patients

Ring melanoma of the ciliary body is a rare variant of uveal melanoma that has a poor prognosis. Only isolated cases have been reported in the literature.

A retrospective review of the clinical features, management, histopathology, and prognosis of 23 consecutive patients with ring melanoma of the ciliary body was performed.

Of 8,800 patients with uveal melanoma treated on the Oncology Service at Wills Eye Hospital over a 25-year period, only 23 patients (0.3%) were found to have ring melanoma of the ciliary body. The mean patient age was 59 years (median, 63 years; range, 8-81 years). The only visual symptom was blurred vision in 17 patients (74%), and the other six patients (26%) were asymptomatic. At the initial presentation elsewhere, melanoma was recognized in 13 cases (57%). In the remaining 10 cases (43%), the initial clinical diagnosis was glaucoma in three (13%), iris nevus in three (13%), cataract in two (9%), ciliary body detachment in one (4%), and iridocyclitis in one (4%). The patients were observed elsewhere for a mean of 3 months before the diagnosis of melanoma was suspected and referral to Oncology Service was made. On examination, the tumor involved a mean of eight clock hours of the ciliary body. Seven patients (30%) had complete circumferential (360 degrees) involvement of the ciliary body, and 16 (70%) had incomplete (180-360 degrees) ring involvement. The mean tumor thickness was 8 mm. Associated findings included neovascularization of the iris in one case (4%), shallow anterior chamber in 11 (48%), anterior chamber inflammation in five (22%), cataract in nine (39%), lens indentation in eight (35%), and lens subluxation in three (13%). A prominent episcleral (sentinel) vessel (17 cases, 74%), multilobulation of the mass (19 cases, 83%), blockage of light on transillumination (23 cases, 100%), and ultrasonographic hollowness with intrinsic pulsations (23 cases, 100%) were important features differentiating this tumor from simulating conditions. The tumor was managed with enucleation in all 23 patients. Histopathologic studies revealed epithelioid cell-type melanoma in two patients (9%), mixed cell-type in 17 (74%), and spindle cell-type in four (17%). Extraocular extension was present in eight patients (35%). Metastasis developed in 12 of 23 patients (52%) after a mean follow-up of 55 months.

Ring melanoma of the ciliary body is a rare tumor that can remain hidden from ophthalmoscopic examination. Certain features, such as prominent episcleral sentinel vessels, multilobulation of the mass, light blockage on transillumination, and ultrasonographic hollowness with intrinsic vascular pulsations, suggest the diagnosis. The life prognosis is poor.