Orbital metastasis from prostatic carcinoma. Identification by an immunoperoxidase technique.

A patient was seen initially with an orbital tumor causing blindness of the left eye. Although disseminated prostatic carcinoma was found, the origin of the orbital tumor was not established until prostate antigen was demonstrated in biopsy specimens by an immunoperoxidase technique. Orbital metastasis from prostatic carcinoma has been reported in 16 cases. Confirmation of the diagnosis may be difficult and, in the past, has largely been indirect as judged by clinical trial. The immunoperoxidase technique for detecting prostate antigen in tissue sections is both sensitive and specific. Application of this technique resulted in the diagnosis of this technique resulted in the diagnosis of this unusual manifestation of metastatic prostate cancer. The possibility of additional clinical applications of this immunohistochemical technique within the field of ophthalmology is raised.