Oral benign neoplasms: A retrospective study of 790 patients over a 14-year period.

INTRODUCTION AND OBJECTIVE: Oral benign neoplasms (OBNs) exhibit some features that can guide the professionals to the correct diagnosis and best treatment. Through retrospective studies, medical records can be reviewed to better describe a given population and, furthermore, help clinicians in routine practice. In this context, the objective of this paper was to analyze the cases of OBNs of an oral pathology referral department, from 2003 to 2017, in order to better understand their epidemiological and clinicopathological characteristics. METHODS: A total of 8355 histopathological reports were analyzed. Lesions diagnosed as OBNs were selected and the following variables were recorded: gender, age, histological type of the lesion, anatomical location, rate and pattern of growth, type of base, color, symptomatology and diagnostic hypotheses on clinical examination. RESULTS: OBNs represented 9.4% of all lesions diagnosed. The most frequent histopathological types were fibroma (39.9%), papilloma (22%), fibroblastoma (13.1%), lipoma (10.2%) and hemangioma (6.1%). Overall, most cases affected females (n=518; 65.6%) and in the fifth decade of life (n=148; 18.7%). The oral mucosa was the most common site (n=265; 33.5%). The most common features of each OBN were also highlighted. CONCLUSION: The most common OBNs were fibroma, papilloma, fibroblastoma, lipoma and hemangioma. Overall, the OBN presented common clinical features; however, in particular cases, there are some characteristics that can lead the professionals to the correct diagnosis. Nevertheless, in general, histopathological analysis must be performed to confirm diagnosis. Intraosseous tumors and large lesions may require imaging tests to help diagnosis.

Oct-4 and CD44 in epithelial stem cells like of benign odontogenic lesions.

Benign epithelial odontogenic lesions are great clinical importance entities that develop in the jaws from the tissues that form teeth. It has been shown that benign and malignant tumors are present in a large number of tumor stem cells, which has great implications in the development of these lesions. Oct-4 and CD44 have been demonstrated as important markers for tumoral stem cells. The aim of this study was investigate the presence of stem cell markers Oct-4 and CD44 in benign epithelial odontogenic lesions. Twenty odontogenic keratocysts (OKC), 20 ameloblastomas (AMB) of the solid/multicystic type and 20 adenomatoid odontogenic tumors (AOT) were retrospectively analyzed for immunohistochemical detection of Oct-4 and CD44 in their epithelial component. All cases were positive for the two markers, with the majority exhibiting a high expression. Analysis of the expression of Oct-4 revealed no statistically significant differences (p = 0.406) between the lesions studied. Regarding CD44, there was a significant difference between the cases of AMB and AOT in relation with OKC, with the latter presenting a greater labelling (p = 0.034). No statistically significant correlation between Oct-4 and CD44 was observed in the lesions. In our findings, the presence of stem cell-like phenotype at various sites of the epithelial component of the odontogenic lesions was identified, suggesting its possible participation in histogenesis and differentiation without, however, exerting influence on the aggressiveness of the lesions.

Análise da imunoexpressão de Oct- 4 e C44 em lesões odontogênicas epiteliais benignas / Immunohistochemical analysis of oct-4 and C44 in benign epithelial odontogenic injuries

Lesões odontogênicas epiteliais benignas são entidades de grande importância clínica que se desenvolvem nos ossos maxilares a partir dos tecidos que formam os dentes. Tem sido demonstrado que em tumores benignos e malignos, estão presentes um grande número de células tronco tumorais, as quais tem grandes implicações no desenvolvimento dos tumores. Oct-4 e CD44 têm sido demostrados como importantes marcadores para células-tronco tumorais. O objetivo deste estudo foi identificar células epiteliais que expressam marcadores de células tronco através da expressão imuno-histoquímica de Oct-4 e CD44 em uma série de casos de lesões odontogênicas epiteliais benígnas. A amostra foi constituída por 20 casos de ceratocisto odontogênico (CCO), 20 caos de Ameloblastoma sólido/multicístico e 20 casos de Tumor Odontogênico Adenomatoide (TOA). A expressão de Oct-4 e CD44 foi avaliada no epitélio das lesões através do percentual de células positivas(PP) e da intensidade da expressão ( IE ), sendo realizado o somatório destes escores, resultando na Pontuação de Imunomarcação Total (PIT) que variou de 0 a 7. Os resultados do presente estudo foram analisados pelo valor da pontuação de PIT. Todos os casos apresentaram positividade para os dois marcadores e a maioria exibiu alta expressão para ambos os marcadores.

A análise da expressão de Oct-4 não revelou diferenças estatisticamente significativas (p = 0,406) entre as lesões estudadas. Com relação à expressão do CD44, houve diferença estatisticamente significativa entre os casos de ameloblastoma e CCO, apresentando este último maior número de casos no score 7 (p = 0,034). Na analise da correlação da imunoexpressão de ambos os marcadores nas três lesões estudadas, não houve correlação estatisticamente significativa . Os resultados do presente estudo identificaram a presença de células com características troncais dispostas em locais variados do componente epitelial das lesões ora estudadas sugerindo a sua possível participação na histogênese e diferenciação em lesões odontogênicas epiteliais benignas contribuindo assim para o desenvolvimento destas lesões. (AU)

Benign epithelial odontogenic lesions are great clinical importance entities that develop in the jaws from the tissues that form teeth. It has been shown that in benign and malignant tumors, are present in a large number of tumor stem cells, which has great implications in the development of these lesions. Oct-4 and CD44 have been demos as important markers for tumoral stem cells. The objective of this study was to identify epithelial cells expressing stem cell markers by immunohistochemical expression of Oct-4 and CD44 in a series of cases of benign epithelial odontogenic lesions. The sample was comprised of 20 cases of odontogenic keratocyst (OKC), 20 cases of solid/multicystic ameloblastoma and 20 cases of adenomatoid odontogenic tumor (AOT). The expression of Oct-4 and CD44 was evaluated in epithelial lesions using the percentage of positive cells (PP) and the intensity of expression (IE), being realized the sum of these scores, resulting in Total Immunostaining Score (TIS) ranging 0 to 7.

The results were submitted to the appropriate statistical test (nonparametric Kruskal-Wallis and Spearman correlation coefficient). All cases were positive for both markers and most showed high expression of both markers. The analysis of Oct-4 expression revealed no statistically significant differences (p = 0.406) among the studied lesions. Regarding the CD44 expression, there was a statistically significant difference between the cases of ameloblastoma and TOA in relation to the CCO, with the latter show more cases in the score 7 (p = 0.034). In the correlation analysis of the immunoreactivity of both markers in the three lesions studied, there was no statistically significant correlation. The results of this study identified the presence of cells with stemness characteristics arranged at various sites in the epithelial component of the studied lesions suggesting their possible role in the histogenesis and differentiation in benign epithelial odontogenic lesions, thus contributing to the development of these lesions. (AU)