The association of non-small-cell lung cancer, focal segmental glomerulosclerosis, and platelet dysfunction.

Neoplasm-related nephrotic syndrome exhibiting focal segmental glomerulosclerosis (FSGS) has been reported mainly in patients with hematologic malignancies. The association of FSGS with carcinoma is very rare and nephrotic syndrome caused by FSGS has not yet been reported in patients with lung cancer. We report a case of nephrotic syndrome caused by FSGS in a 61-year-old man with advanced non–small-cell lung cancer. In addition, platelet dysfunction evidenced by prolonged bleeding time was noted. The renal problem and prolonged bleeding time resolved dramatically during radiotherapy for lung cancer. We speculate that both FSGS and prolonged bleeding time are paraneoplastic syndromes associated with lung cancer, although the underlying mechanisms of both conditions remain to be elucidated.