Clinicopathological and immunohistochemical study of 39 cases of Adenomatoid Odontogenic Tumour: a multicentric study.

Adenomatoid Odontogenic Tumour (AOT) is a relatively uncommon odontogenic lesion and few studies describing its cytokeratin profile have been reported in the English-language literature. Thirty-nine cases of AOT from three Oral Diagnosis services (Brazil, Mexico and Guatemala) were studied, considering their clinical, radiographic, and histological features and immunohistochemical expression of cytokeratins (AE1/AE3, 34betaE12, CK1, CK5, CK6, CK7, CK8, CK10, CK13, CK14, CK16, CK18, and CK19), vimentin and Ki-67. Sixty five percent of cases affected women, anterior maxilla was the preferred site and radiographically most cases showed unilocular radiolucency with well defined sclerotic borders. Calcifying epithelial odontogenic tumour (CEOT)-like areas were found in 36 out of 39 cases, and 10 cases showed positivity for Congo red in polarized light. All cases were positive for AE1/AE3, 34betaE12, CK5, CK14 and CK19. CEOT-like areas were negative for CK 19. Vimentin was also expressed in 27 cases and this profile may indicate the existence of a variable phenotype in certain areas of the tumour. There were no recurrences after surgical treatment, and this can be related to the low proliferative activity observed in all cases with Ki-67 marker.