K-ras oncogene mutations in osteoclast-like giant cell tumors of the pancreas and liver: Genetic evidence to support origin from the duct epithelium

William H. Westra, Patrick Sturm, Paul Drillenburg, Michael A. Choti, David S. Klimstra, Jorge Albores-Saavedra, Anthony Montag, G. Johan A Offerhaus, Ralph H. Hruban

Research output: Contribution to journalArticle

90 Scopus citations

Abstract

Osteoclast-like giant cell tumors (OCGTs) of the pancreas and liver are enigmatic tumors. Despite their striking morphologic resemblance to certain mesenchymal tumors of bone and tendon sheath, it has been suggested that these tumors may, in fact, arise from epithelial precursors. It is also unclear whether the osteoclast-like giant cells in OCGTs are neoplastic or nonneoplastic. We identified OCGTs of the pancreas and liver that were associated with atypical intraductal epithelial proliferations or mucinous cystic neoplasms. To determine the relationship between the noninvasive epithelial proliferations and the infiltrating OCGTs, each individual component was analyzed for mutations at codon 12 of the K-ras oncogene. Four of the five-duct epithelial lesions harbored activating mutations of the K- ras oncogene. In each case, the same K-ras mutation was also present in the mononuclear cells from the paired OCGT. Moreover, these same mutations were detected when the osteoclast-like giant cells were individually microdissected and analyzed. A panel of immunohistochemical stains was performed, and the osteoclast-like giant cells demonstrated macrophage differentiation. These cells were consistently reactive for the monocyte/macrophage marker KP1, but showed absent staining for a panel of epithelial markers. The infiltrating mononuclear cells lacked strong staining for epithelial markers and monocyte/macrophage markers. These findings suggest that OCGTs of the pancreas and liver are undifferentiated carcinomas that arise directly from intraductal epithelial precursors. The finding of K- ras mutations in the osteoclast-like giant cells may reflect their propensity to phagocytize tumor cells.

Original languageEnglish (US)
Pages (from-to)1247-1254
Number of pages8
JournalAmerican Journal of Surgical Pathology
Volume22
Issue number10
DOIs
StatePublished - Oct 1 1998

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Keywords

  • Giant cell tumor
  • K-ras
  • Oncogenes
  • Osteoclast
  • Osteoclast- like
  • Pancreas
  • Pancreatic neoplasms

ASJC Scopus subject areas

  • Anatomy
  • Surgery
  • Pathology and Forensic Medicine

Cite this

Westra, W. H., Sturm, P., Drillenburg, P., Choti, M. A., Klimstra, D. S., Albores-Saavedra, J., Montag, A., Offerhaus, G. J. A., & Hruban, R. H. (1998). K-ras oncogene mutations in osteoclast-like giant cell tumors of the pancreas and liver: Genetic evidence to support origin from the duct epithelium. American Journal of Surgical Pathology, 22(10), 1247-1254. https://doi.org/10.1097/00000478-199810000-00010