Nephrotic syndrome due to focal glomerulosclerosis and undifferentiated carcinoma

In neoplastic disorder-related nephrotic syndrome, focal glomerulosclerosis (FGS) has been reported mainly in hematological disorders like minimal change nephrotic syndrome (MCNS) in association with presumed T lymphocyte dysfunction. The association of FGS with cancer or solid tumor is rare. We report a case of nephrotic syndrome due to FGS in a patient with undifferentiated adenocarcinoma of the cystic duct. Although the underlying mechanism is unclear, the development of FGS seemed to be related to the poor histological differentiation of the cancer in the possibility of production of an active peptide.