Metastatic carcinoid to the choroid.

This article describes the seventh published case of metastatic carcinoid to the choroid. Only two prior cases have been treated conservatively, one using chemotherapy and the other using photocoagulation and proton beam irradiation. Our patient was unique since she was the first to have conservative therapy by implantation of a radon ring. Initial results were clinically promising, although repeated ultrasound testing actually showed minimal decrease in tumor size. Subsequently, a large retinal detachment caused marked visual deterioration. Persistent pain from neovascular glaucoma prompted later enucleation, and silver staining as well as electron microscopic studies were performed on the choroidal lesion. It was found that the radon ring had little histologic effect on the viability of the tumor cells. This contrasted with an earlier report of the successful treatment of two much smaller choroidal lesions, using external proton beam irradiation. From our pathologic evaluation, we believe that the metastatic carcinoid tumor should be considered relatively radioresistant.