Osteoclast-like Giant Cell Tumor of the Parotid Gland Accompanied with Carcinoma ex Pleomorphic Adenoma

The origin of osteoclast-like giant cell tumor (OGCT) of the salivary gland has been debated because the prototypic cells of osteoclast-like cells and mononuclear stromal cells are largely unexplained in this gland. Bone marrow-derived CD14+ and CD45+ monocyte-derived multipotential cells (CD14+/CD45+ MOMC) may be one of the possible origins of OGCTs of salivary glands, which have never been explored in salivary OGCTs. We present a case of OGCT accompanied with carcinoma ex pleomorphic adenoma in the parotid gland of a 67-year-old Korean female. The tumor presented as a rapidly growing cervical mass comprising a central area of carcinoma ex pleomorphic adenoma and a peripheral circumferential area of OGCT. The immunohistochemical staining pattern was phenotypically consistent with bone marrow-derived CD14+/CD45+ MOMC. This case is the first report of a salivary OGCT in Korea.