Odontogenic tumor with combined characteristics of adenomatoid odontogenic and calcifying epithelial odontogenic tumors.

A very rare odontogenic epithelial tumor with the combined characteristics of an adenomatoid odontogenic tumor (AOT) and calcifying epithelial odontogenic tumor (CEOT) was found in a 27 year old female. The histopathology, immunohistochemistry of keratin, lectin-binding patterns and distribution of carbonic anhydrase were determined. The nature of the calcified bodies was also examined biophysically. The tumor consisted of cuboidal and columnar odontogenic epithelial cells in the cystic wall, and AOT and CEOT in the central cavity. Odontogenic epithelial cells forming the cyst wall in the CEOT were positive for TK- and KL1-keratins, while that detected with PKK1 antibody was absent in the tumorous epithelium. Lectin binding of tumor epithelial cells was examined with Concanavalin A (Con A), peanut agglutinin (PNA), soybean agglutinin (SBA), dolichos biflorus agglutinin (DBA), wheat germ agglutinin (WGA), ricinus communis agglutinin (RCA-I), and ulex europeus agglutinin I (UEA-I) lectins, and the tumor epithelium indicated existence of glucose, mannose, Gal, GalNAc, and GlcNAc residues. The lectin binding patterns of the calcified material showed an increased intensity by enzymatic pretreatments. With an electron probe X-ray microanalyser (EPMA), the calcified lesions gave a high peak for calcium ion and for phosphorus ion and a low one for magnesium ion, as obtained from line and surface analysis.