Immunohistochemical evaluation of yes-associated protein molecule in the odontogenic epithelium of different histopathological variants of ameloblastoma and unicystic ameloblastoma.

Background: Ameloblastoma is one of the major odontogenic neoplasms with an invasive and recurrence potential. Its tumourigenesis and proliferative capacity can be attributed to the activation or inactivation of certain molecular signalling pathways. Hippo signalling pathway is known to regulate diverse physiological processes related to mitosis and organ growth and is an emerging tumour suppressor pathway, the dysfunction of which is implicated in various diseases including cancers. Yes-associated protein1 (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are the downstream effectors in the Hippo cascade, which on nuclear activation leads to cellular proliferation in various tumours. Aim: The current study was undertaken to evaluate the expression of YAP in various histopathological variants of ameloblastoma and unicystic ameloblastoma. Materials and Methods: Fifty formalin-fixed paraffin-embedded tissue samples of histopathologically diagnosed cases of ameloblastoma, and 10 histopathologically diagnosed cases of unicystic ameloblastoma were obtained from the departmental archives to evaluate the immunohistochemical expression of YAP both manually and by software analysis. Results: More than 90% of cases of conventional ameloblastoma and unicystic ameloblastoma elicited positive expression of YAP. No statistical difference was found among different histopathological variants of conventional ameloblastoma. Significant difference between the means of all four quantitative score groups was observed. Conclusion: In view of the modulating effect of YAP in tumourigenesis and its higher expression in ameloblastoma, further exploration of this molecule appears to be a promising area of research.

Sclerosing polycystic adenosis of minor salivary glands: Report of a rare case with diagnostic approach and review of literature.

Sclerosing polycystic adenosis (SPA) is an uncommon entity occurring in the salivary glands, with majority of the cases reported in major salivary glands reminiscent of fibrocystic disease of the breast. SPA arising in minor salivary glands of the oral cavity constitutes an exceedingly rare phenomenon. Here, we report a case of SPA that presented as a solitary, submucosal mass on the left lower labial mucosa in a 19-year-old male. The pathology features and a clinicopathologic diagnostic approach highlighting key features are discussed here. Similar cases published in the English literature are reviewed.