BackgroundOral focal mucinosis (OFM) is a rare soft tissue lesion of unknown etiology that exhibits tumor-like growth. It is considered the oral counterpart of cutaneous focal mucinosis or cutaneous myxoid cyst. This is a retrospective study of oral OFM diagnosed over a period of 42 years at an oral pathology service.Material and MethodsClinical, histopathological and immunohistochemical data were analyzed. Alcian blue staining and S-100 immunohistochemistry were performed.ResultsEleven cases were retrieved (4:1 female-to-male ratio). The mean age was 44 years. The gingiva was the most affected site. The main clinical presentation was sessile or pedunculated lesions of fibrous or hyperplasic appearance, most of them asymptomatic. Positive Alcian blue staining and absence of S-100 protein were observed in all specimens, which supported the histological diagnosis of OFM. Surgical excision was the treatment of choice.ConclusionsAlthough rare, this study supports the inclusion of OFM in the differential diagnosis of intraoral myxoid lesions. Key words:Oral focal mucinosis, myxomatous lesion, connective tissue diseases, diagnosis.

BackgroundAmeloblastoma (AMB), odontogenic keratocyst (OKC) and adenomatoid odontogenic tumor (AOT) are epithelial odontogenic lesions with diverse biologic profiles. Defects in regulation of apoptosis and cell cycle may be involved in the development and progression of those lesions, therefore we aimed to investigate the expression of Bcl-2, Bax and p53 to better understand the possible role of these proteins in AMBs, OKCs and AOTs.Material and MethodsThe studied sample consisted of 20 AMBs, 20 OKCs and 20 AOTs. Immunohistochemistry technique was performed for the antibodies p53, Bcl-2 and Bax. Immunoreactivity was observed in the epithelial component and positive cells were counted in five fields (100x magnification). Statistical analysis was performed with Kruskal-Wallis and Spearman tests (p<0.05).ResultsAll lesions exhibited staining for the three studied proteins. There was no statistically significant associations between the expression of proteins and the lesions, however we identified a positive correlation between the expression of p53 and Bcl-2 (r = 0.200) and a negative correlation between p53 and Bax expressions (r = -0.100). In addition, p53 and Bax were similarly expressed between AMBs and OKCs. Bcl-2 was similarly expressed in AMBs and AOTs.ConclusionsApoptosis regulatory proteins, as well as cell cycle proteins, are differently expressed in epithelial odontogenic lesions and their expression is possibly related to the biological behavior of AMB, OKC and AOT. Key words:Odontogenic tumors, apoptosis, apoptosis regulatory proteins, p53 tumor suppressor protein, immunohistochemistry.