Subretinal fluid examination of LDH, PGI, and CEA in a case of metastatic bronchogenic carcinoma of the choroid

Abstract

A 58-year-old white male with a history of bronchogenic carcinoma presented with a total retinal detachment overlying a choroidal metastasis. His main tumor burden had been extirpated by pneumonectomy followed by radiation therapy four months prior to admission. With the development of a painful, glaucomatous eye, unresponsive to conventional therapy, enucleation was performed. Histologic examination of the enucleated globe revealed a metastatic tumor to the choroid, consistent with primary bronchogenic carcinoma. Aqueous humor and plasma examination revealed elevated ratios (Aqueous humor:Plasma) of lactate dehydrogenase (LDH) and phosphoglucose isomerase (PGI). Furthermore, subretinal fluid examination demonstrated concentrations of LDH and PGI higher than aqueous humor. While the level of carcinoembryonic antigen (CEA) in the plasma was normal (less than 2.5 ng/ml) following pneumonectomy, it was 121 ng/ml in the subretinal fluid. This would suggest that a choroidal lesion alone, in the absence of a clinically detectable primary tumor, is insufficient to elevate the plasma CEA.