Osteoclastlike giant cell tumor of the salivary gland

Giant cell tumor of the salivary gland is extremely rare, with only 15 cases published in the English literature. The tumor characteristically contains a mixture of multinucleated giant cells, resembling osteoclasts of bone, and neoplastic mononuclear cells. In about half of the reported cases, there is an associated carcinomatous component. We are reporting an additional case of giant cell tumor of the parotid gland that was initially misinterpreted as an extraosseous osteosarcoma in the biopsy specimen. The histologic and immunohistochemical findings as well as a review of the literature with discussion of the histogenesis of this unusual neoplasm are presented.