Two distinct pathologic types of giant cell tumor of the vulva. A report of two cases

Giant cell carcinoma of the vulva has been described as a distinctive primary tumor of the vulva associated with multinucleated tumor giant cells and nuclear pleomorphism. These tumors have been reported to have a poorer prognosis than does squamous cell carcinoma, to which they are thought to be related. Two women were treated for primary vulvar malignancies possessing the morphologic features of giant cell tumor. Electron microscopy was not beneficial in distinguishing the tumors. A panel of immunoperoxidase procedures, including AE 1/3, 35 beta H-11, carcinoembryonic antigen, epithelial membrane antigen, HMB-45, S-100, leukocyte common antigen, placentalike alkaline phosphatase, alpha-1-antichymotrypsin and vimentin made it possible to distinguish the two tumors and characterized one as a nodular amelanotic melanoma with multinucleate tumor giant cells and the second as a squamous cell carcinoma with tumor giant cells. The latter term should replace the term giant cell carcinoma. Histologic criteria can help define this tumor.