Response of choroidal leiomyoma to treatment with proton beam radiation.

Overview

PURPOSE: Uveal leiomyoma is a rare, benign smooth muscle neoplasm usually diagnosed only after local resection or enucleation. We describe a single interventional case report with clinicopathologic correlation of an intraocular leiomyoma responding to proton beam radiation. CASE REPORT: A 51-year-old woman presented with a choroidal mass in the left eye that was initially diagnosed as a choroidal melanoma. The neoplasm was treated with a total of 70 cobalt gray equivalents of external proton beam radiation in 5 fractions over 7 days. Biannual follow-up examinations over 3 years showed a funduscopically and ultrasonographically regressing tumor. The left eye was enucleated approximately 3 years postradiotherapy because of progressively increasing pain secondary to elevated intraocular pressure from neovascular glaucoma. Microscopic and immunohistochemical examination of the mass revealed a choroidal neoplasm expressing smooth muscle antigens consistent with a uveal leiomyoma. CONCLUSION: Uveal leiomyoma appears to be responsive to proton beam radiation, and radiotherapy may serve as an alternative to primary enucleation or local resection. Additional studies are necessary to determine whether radiotherapy of smaller tumors might render better results for vision and globe preservation.