Calcifying epithelial odontogenic tumour: a case showing features of malignancy.

A case of malignant calcifying epithelial odontogenic tumour is reported in a 75-year-old man. Evidence of local tissue invasion and lymph-node metastasis is presented. Immunoperoxidase studies of the neoplastic cells and tumour amyloid were negative for a variety of antigens, including the epithelial markers CEA and keratin. The histological and clinical findings are discussed.