Fibrocalculous Pancreatic Diabetes (FCPD) Presenting with Severe Hyponatremia in 58-Year-Old Male: A Case Report

Fibrocalculous Pancreatic Diabetes (FCPD) is a rare, tropical form of secondary diabetes mellitus caused by chronic calcific pancreatitis, predominantly seen in developing countries. It is characterized by pancreatic ductal calculi, exocrine insufficiency, and insulin-requiring diabetes with relative ketosis resistance. We report a case of a 58-year-old non-alcoholic male from West Bengal, India, who presented with severe hyponatremia (serum sodium 117 mEq/L) and was found to have poorly controlled diabetes (HbA1c 8.2%) along with imaging evidence of chronic calcific pancreatitis — dilated main pancreatic duct with multiple calculi and parenchymal calcification on both ultrasonography and CECT abdomen. The patient was also found to have microalbuminuria, normocytic anemia, and echogenic floaters in the urinary bladder. This case highlights the occurrence of FCPD in an older patient and the importance of recognizing this entity in the differential diagnosis of diabetes with abdominal imaging abnormalities in tropical settings.