Density of Langerhans cells in the keratocystic odontogenic tumor / Densidade das c??lulas de Langerhans no tumor odontog??nico queratoc??stico

Tumor odontog??nico queratoc??stico (TOQ) ?? uma les??o odontog??nica de car??ter distinto que afeta frequentemente ossos maxilares. C??lulas de Langerhans (CLs) s??o c??lulas dendr??ticas especializadas, respons??veis pela apresenta????o de ant??genos aos linf??citos T nas superf??cies cut??nea e mucosa. OBJETIVO: Este estudo analisou a express??o imuno-histoqu??mica das CLs em les??es de TOQ. MATERIAIS E M??TODOS: Quinze casos de TOQ foram estudados utilizando o marcador anti-CD1a. RESULTADOS: As CLs foram observadas em todos os 15 casos analisados. Essas c??lulas estavam concentradas em ??reas de hiperplasia do epit??lio c??stico, especialmente naquelas que apresentavam alta concentra????o de c??lulas inflamat??rias. Em adi????o, foi encontrada associa????o significativa entre n??mero de CLs e ??reas do epit??lio c??stico que apresentavam hiperplasia (Mann-Whitney test, p = 0.0223). O formato e a localiza????o dessas c??lulas no epit??lio dos TOQs foram vari??veis. CONCLUS??O: O menor n??mero de CLs encontrado no revestimento c??stico atr??fico dos TOQs pode ser atribu??do ?? imunovigil??ncia deficiente e isso pode resultar em comportamento biol??gico localmente agressivo.Keratocystic odontogenic tumors (KOTs) are distinct odontogenic lesions commonly affecting the mandible bones. Langerhans cells (LCs) are specialized dendritic cells responsible for the presentation of antigens to T lymphocytes in mucosal and cutaneous surfaces. OBJECTIVE: This study analyzed the immunohistochemical expression of LCs in KOTs. MATERIALS AND METHODS: Fifteen cases of KOTs were studied using the anti-CD1a marker. Results: LCs were observed in all 15 cases analyzed. They were found to be concentrated in areas of cystic epithelial hyperplasia, mainly in those areas presenting higher concentration of inflammatory cells. Furthermore, a significant association between the number of LCs and areas of cystic epithelium presenting hyperplasia (Mann-Whitney test, p = 0.0223) was observed. The shape and location of these cells in KOTs epithelium were variable. CONCLUSION: The lower number of LCs observed on atrophic cystic epithelium of KOTs may be due to decreased epithelial immunosurveillance and this may result in locally aggressive invasiveness