Undifferentiated Carcinoma of the Pancreas with Osteoclast-Like Giant Cells: Initially Diagnosed as Solid Pseudopapillary Tumor

Abstract

Undifferentiated carcinoma of the pancreas with osteoclastlike giant cells (UCPOGC), first described by Juan Rosai in 1968, is a rare, highly malignant exocrine tumor. UCPOGC is now classified by the World Health Organization as a rare variant of ductal adenocarcinoma, based on the epithelial origin of this tumor. In the early reports on this tumor it was suggested that they may have a more favorable prognosis compared with the usual ductal adenocarcinoma. UCPOGC tends to present at the mean age of 60 years, and has the same sex distribution. Microscopic findings consist of atypical mononuclear round cells and abundant osteoclast-like multinucleated giant cells, thus, mimicking a giant cell tumor of the bone. Here, we report a case of UCPOGC and describe its characteristics.