Undifferentiated carcinoma with osteoclast-like giant cells of the pancreas arising from an intraductal papillary mucinous neoplasm

Abstract

Undifferentiated carcinoma of the pancreas with osteoclast-like giant cells is a rare pancreatic tumor of unclear origin. This case reports a 72-year-old male with bloating and indigestion for about six years who was found to have a 5 cm laterally spreading ampullary mass and a 1.3 cm solid and cystic distal pancreas body mass on esophagogastroduodenoscopy (EGD) and endoscopic ultrasound (EUS). Histological examination of the pancreatic mass showed an undifferentiated carcinoma with osteoclast-like giant cells, contiguous with and apparently arising from an IPMN. Rare areas of glandular morphology within the invasive carcinoma, as well as patchy expression of epithelial markers and close physical association with an IPMN, clearly support an epithelial origin of this neoplasm and also suggest neoplastic progression from a preneoplastic ductal lesion to an invasive carcinoma, similar to the histogenesis of ductal-type pancreatic adenocarcinoma. Molecular analysis of the invasive carcinoma revealed mutations typical of pancreatic ductal carcinoma. Identical mutations were then identified within the intraductal mucinous neoplasm, consistent with origin of this rare pancreatic carcinoma subtype from IPMN. Keywords: UC-OGC, IPMN, Pancreas, K-ras, Neoplasm