Surgically resected undifferentiated carcinoma with osteoclast-like giant cells of the periampullary region involving the orifice of the papilla of Vater: Report of a case.

Undifferentiated carcinomas with osteoclast-like giant cells are rare periampullary neoplasms, which morphologically mimic giant cell tumors of the bone. The terminology, histogenesis, biological behavior, and chemosensitivity of these tumors, and their treatment protocol, remain controversial. We report the case of a 71-year-old man with periampullary carcinoma who underwent pancreaticoduodenectomy under the diagnosis of periampullary carcinoma. Histologically, the neoplasm was composed of undifferentiated cells and evenly spaced osteoclast-like giant cells. Liver and paraaortic lymph node metastases were detected 6 months later and were treated effectively with intravenous gemcitabine. The patient remains in remission 2 years after surgery.