Unicentric Castleman Disease Coexisting With Type 2 Autoimmune Pancreatitis: A Case Report Mimicking Pancreatic Cancer and Near-Whipple Surgery.

This case describes a 46-year-old man presenting with epigastric pain, weight loss, and obstructive jaundice, initially misdiagnosed as pancreatic cancer due to a pancreatic head mass compressing the common bile duct. Intraoperative biopsies during an aborted Whipple procedure revealed coexisting autoimmune pancreatitis and Castleman disease. This case highlights the diagnostic challenges of Castleman disease, its potential association with autoimmune pancreatitis, and the critical role of histological analysis in differentiating it from malignancy.