CANCER-ASSOCIATED RETINOPATHY SYNDROME - A CASE OF SMALL-CELL LUNG-CANCER EXPRESSING RECOVERIN IMMUNOREACTIVITY

Cancer-associated retinopathy (CAR) syndrome is a rare paraneoplastic neuropathy syndrome often found in patients with small cell lung cance r (SCLC). Serological studies have indicated that the process could in clude autoimmune reactions directing retinal antigens. Recently, the C AR antigen was identified as a photoreceptor protein, recoverin, by sc reening retinal proteins using the CAR patient's serum. The present ca se of SCLC showed rapidly deteriorated bilateral visual acuity lacking the inflammatory findings at the retina which were compatible with CA R. The immunohistochemical study revealed that the cancer cells expres sed recoverin or recoverin-like immunoreactivity, This is the first ob servation in CAR syndrome. The presence of recoverin or recoverin-like immunoreactivity in SCLC with CAR syndrome supports the hypothesis th at the cancer-retina immunologic cross-reaction contributes to visual loss in this syndrome.