Immunohistochemical detection of amelogenin and cytokeratin 19 in epithelial odontogenic tumors.
OBJECTIVE
Epithelial odontogenic tumors exhibit considerable histological variation and are classified into several benign and malignant entities. Expression of amelogenin and cytokeratin 19 (CK19), that are potentially useful polypeptides for identification of odontogenic epithelial components, was evaluated in various types of epithelial odontogenic tumors.


METHODS
Specimens of 33 ameloblastomas, three calcifying epithelial odontogenic tumors (CEOTs), two clear cell odontogenic tumors (CCOTs) and five malignant ameloblastomas were examined by immunohistochemistry using anti-amelogenin and anti-CK19 antibodies.


RESULTS
Immunohistochemical reactivity for amelogenin was detected in many peripheral columnar or cuboidal cells and some central polyhedral cells in ameloblastomas, and histological variants showed various degrees of amelogenin expression. Expression of CK19 was diffusely present in neoplastic cells in ameloblastomas, and decreased expression was found in keratinizing cells of acanthomatous variants and some neoplastic cells of desmoplastic variants. In CEOTs, immunohistochemical reactivity for amelogenin was detected in neoplastic cells and intercellular amyloid-like materials, whereas CK19 was expressed in neoplastic cells. CCOTs showed positive reactivity for amelogenin and CK19 in neoplastic cells. Malignant ameloblastomas exhibited various degrees of amelogenin expression with constant CK19 expression in neoplastic cells.


CONCLUSIONS
Diverse types of epithelial odontogenic tumors express amelogenin and CK19, suggesting that these tumors have ameloblastic differentiation or odontogenic epithelial properties.
Kumamoto
H
H
Department of Oral Pathology, Tohoku University School of Dentistry, Sendai, Japan. kumamoto@mail.cc.tohoku.ac.jp
Yoshida
M
M
Ooya
K
K
D000564:Ameloblastoma / Q000378:metabolism* / Q000473:pathology; D053523:Amelogenin; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D003746:Dental Enamel Proteins / Q000096:biosynthesis*; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000096:biosynthesis*; D009363:Neoplasm Proteins / Q000096:biosynthesis; D009808:Odontogenic Tumors / Q000378:metabolism* / Q000473:pathology
D053523:Amelogenin; D014408:Biomarkers, Tumor; D003746:Dental Enamel Proteins; D009363:Neoplasm Proteins; D007633:Keratins