KRAS ONCOGENE MUTATIONS SUGGEST A COMMON HISTOGENETIC ORIGIN FOR PLEOMORPHIC GIANT-CELL TUMOR OF THE PANCREAS, OSTEOCLASTOMA OF THE PANCREAS, AND PANCREATIC DUCT ADENOCARCINOMA

Giant cell neoplasms of the pancreas are rare tumors of uncertain hist ogenesis. Mutation of the KRAS oncogene is common in typical pancreati c duct adenocarcinoma. We have analyzed DNA from five pancreatic tumor s with giant cells for mutations in the KRAS and found alterations of the second position of codon 12 in each case (four G > A transitions a nd one G > C transversion). The common mutation pattern in tumors with giant cells and duct adenocarcinoma suggests a common route to malign ant transformation and may indicate a shared histogenesis. We also tes ted 11 cases of malignant fibrous histiocytoma, a histological mimic o f pleomorphic giant cell tumor, for mutations in the KRAS oncogene. Th e absence of KRAS mutations in each of the malignant fibrous histiocyt omas (MFHs) and in other histologically similar tumors may provide ass istance in the differential diagnosis of pleomorphic pancreatic tumors . Copyright (C) 1997 by W.B. Saunders Company.