Castleman's disease, or giant lymph node hyperplasia, occurs most commonly in the mediastinum, with infrequent presentation in the abdominal cavity. We describe a rare occurrence of Castleman's tumor initially seen as a pancreatic mass. The clinical presentation, course, and treatment of this condition are discussed. Clinicians should be aware that giant lymph node hyperplasia may involve the peripancreatic tissues and simulate a pancreatic neoplasm.