ABSTRACT
Undifferentiated carcinoma with osteoclast-like giant cells is a rare neoplasm of exocrine pancreas. Till recently, some cases have been reported, however histogenesis of the tumors are controversial and their characteristic findings have not been described yet. Thirty five-year-old men and 75-year-old men were presented with upper abdominal pain and a palpable mass. On computed tomography, one case showed a well enhancing solid tumor with low density and the other was showed a mainly cystic tumor with peripheral enhancement in the body and tail of the pancreas. One case accompanied multiple metastatic liver masses with subhepatic lymph node enlargement. Tumor staining was seen on angiography. Biopsy and pancreatectomy were performed. Pathological findings revealed tumors composed of neoplastic spindle shaped or pleomorphic large cells with scattered non-neoplastic osteoclast-like giant cells. In one case, there were small foci of adenocarcinoma components in the periphery of the tumor. On immunohistochemical stain, neoplastic cells showed focal positivity for epithelial membrane antigen and vimentin. Tumors were diagnosed as undifferented carcinoma with osteoclast-like giant cells. We report these rare cases with a review of literature.