Comparative histological and immunohistochemical study of ameloblastomas and ameloblastic carcinomas

Abstract

Background: This study aimed to compare the histological and immunohistochemical characteristics of ameloblastomas (AM) and ameloblastic carcinomas (AC). Material and Methods: Fifteen cases of AM and 9 AC were submitted to hematoxilin and eosin (H&E) and immunohistochemical analysis with the following antibodies: cytokeratins 5,7,8,14 and 19, Ki-67, p53, p63 and the cellular adhesion molecules CD138 (Syndecan-1), E-cadherin and β-catenin. The mean score of the expression of Ki-67 and p53 labelling index (LIs) were compared between the groups using the t test. A value of p<0.05 was considered to be statistically significant. Results: All cases were positive for CKs 5, 14 and 19, but negative for CKs 7 and 8. CKs 5 and 19 were positive mainly in the central regions of the ameloblastic islands, while the expression in AC was variable in intensity and localization. CK14 was also variably expressed in both AM and AC. Ki-67 (P=.001) and p53 (P=.004) immunoexpression was higher in AC. All cases were positive for p63, but values were higher in AC. CD138 was mainly expressed in peripheral cells of AM, with a weak positivity in the central areas, while it was positive in most areas of ACs, except in less differentiated regions, where expression was decreased or lost. E-cadherin and β-catenin were weakly positive in both AM and AC.

Differences in E-Cadherin and Syndecan-1 Expression in Different Types of Ameloblastomas

“…Martinez-Martinez et al [19] reported that the expression levels of Ecad and B-catenin were low in ameloblastomas and ameloblastic carcinomas, consistent with our results. This suggests that Ecad is associated with tumor behavior due to the loss of cell adhesion.…”

“…The expression profiles of Ecad, Syn1E, and Syn1S have been evaluated separately in previous studies [12, 14–19]. However, there is minimal research on the comparisons between the expressions of Ecad, Syn1E, and Syn1S in the same system, in which a greater understanding of the behavior of these tumors can be obtained by analyzing their expression profiles.…”

A Rare Case of Sinonasal Ameloblastoma with Immunohistochemistry.

“…It may be helpful to reach a correct diagnosis in doubtful situations. 17 In this case the immunohistochemical markers confirmed diagnosis of ameloblastoma. In all cases of unilateral nasal mass, high index of suspicion of neoplastic etiology is must.…”

IKKβ overexpression together with a lack of tumour suppressor genes causes ameloblastic odontomas in mice

“…Some ameloblastic carcinomas in humans have been proposed to develop from ameloblastomas. 19 Our results suggest that increased IKKβ expression provokes NF-κB activation and a strong inflammatory response that could contribute to the tumoural transformation of the odontogenic epithelium through the uncontrolled release of inflammatory cytokines and facilitate the development of a secondary ameloblastic carcinoma in a preexisting ameloblastic odontoma, although the existence of other driving factors cannot be ruled out.…”