CLEAR-CELL TUMORS OF THE SALIVARY-GLANDS, JAWS, AND ORAL-MUCOSA

Clear cell tumors of the oral mucosa, jaws, and salivary glands consti tute a heterogeneous group of lesions which may be either odontogenic, salivary gland, or metastatic in origin. Clear cells in these prolife rations most frequently result from fixation artifact but may also be the result of cytoplasmic accumulation of water, glycogen, intermediat e filaments, or immature zymogen granules, or a paucity of cellular or ganelles, Odontogenic neoplasms that may be characterized by a predomi nantly clear cell component include odontogenic carcinoma, ameloblasto ma, and calcifying epithelial odontogenic (Pindborg) tumor. Clear cell tumors of salivary gland origin are almost invariably malignant in na ture but they do include two benign lesions; namely, oncocytoma and my oepithelioma. Clear cells in acinic cell carcinoma seldom comprise a s ignificant portion of the tumor whereas clear cell mucoepidermoid carc inomas can readily be identified by an admixture of clear-squamoid, mu cous and intermediate cells. Lesions previously reported as ''clear ce ll adenoma'' ''clear cell carcinoma, or glycogen-rich carcinoma'' can be divided into the distinctive biphasic epithelial-myoepithelial carc inoma and monophasic lesions which have been shown to be either myoepi thelial or ductal in origin. The latter are primarily represented by t he recently described ''hyalinizing clear cell carcinoma.'' The most c ommon metastatic clear cell tumor in the oral mucosa and the jaws is t he renal cell carcinoma. However, metastases of melanoma and malignant clear cell tumors of the prostate, bowel, thyroid, and liver must als o be considered. Copyright (C) 1997 by W.B. Saunders Company.