Undifferentiated Gallbladder Carcinoma with Osteoclast-like Giant Cells: A Case Report

Kang, Yun Kyung

Abstract

Undifferentiated carcinoma with osteoclast-like giant cells (OGCs) is the least common type of gallbladder carcinoma. Here, the author presents a case of undifferentiated gallbladder carcinoma with OGCs in an 81-year-old male patient. Grossly, the tumor was a 10x7 cm sized, polypoid, lumen-filling mass with extensive hemorrhage and necrosis. Microscopically, the tumor was composed of pleomorphic ovoid to spindle cells admixed with numerous OGCs. There was a minute focus of mucosal dysplasia and carcinoma in situ. Immunohistochemically, the mononuclear cells were positive for cytokeratin, p53 and Ki-67, while the OGCs were negative for these markers but positive for CD68. These findings support an epithelial origin for the ovoid to spindle cells and the nonneoplastic reactive histiocytic lineage of the OGCs.