Case Report of Seronegative Cancer-Associated Retinopathy in a Patient with Small Cell Lung Carcinoma

Cancer-associated retinopathy (CAR) is a rare paraneoplastic syndrome characterized by autoimmune destruction of photoreceptor cells. It is associated with several tumor types, including small cell lung carcinoma (SCLC). Corticosteroids have been the mainstay treatment for CAR, although no therapeutic standard has truly been established. A 66-year-old female with significant smoking history and age-related macular degeneration (ARMD) presented with rapidly declining bilateral visual acuity. Ophthalmologic examination findings appeared consistent with the known diagnosis of ARMD but did not otherwise present a clear alternative etiology. Imaging with a computed tomography (CT) scan revealed a right hilar mass which was confirmed to be limited stage SCLC based on a subsequent biopsy and further imaging with a positron emission tomography/computed tomography (PET/CT) scan. Antibody testing was negative for anti-recoverin antibodies. The patient experienced a complete response to chemoradiation with cisplatin and etoposide; however, her ocular symptoms did not respond to a combined treatment approach with corticosteroids, plasmapheresis, and intravenous immunoglobulin (IVIG). While CAR represents a rare condition in SCLC, cases that are seronegative for anti-recoverin are even less common. Further, the diagnosis of CAR by ophthalmologic examination may be more challenging in patients with pre-existing ocular diseases, such as macular degeneration. Clinicians should have suspicion for paraneoplastic blindness in patients with known risk factors for malignancy, whose ocular symptoms are inconsistent with exam findings.