Ocorrência simultânea de cisto dentígero e odontoma composto-complexo causando impacção dentária / Simultaneous occurrence of dentigerous cyst and compound-complex odontoma causing dental impaction

O presente trabalho ilustra e discute essa doença que representa o tumor odontogênico mais comum da prática clínica, o Odontoma. Para tal, apresenta um caso clínico com imagens clínicas e radiográficas esclarecedoras dos aspectos dessa doença, bem como discussão a partir de revisão narrativa de literatura direcionada para a carac-terização da doença. Relata-se o caso de um odontoma composto-complexo, uma forma incomum de odontoma, mas que mantém os demais aspectos usuais, sendo uma mulher de 21 anos com lesão radiopaca em maxila de-tectada devido à não erupção do 23. A remoção cirúrgica seguiu a partir de acesso anterior na maxila e o exame histopatológico mostrou os aspectos típicos de um Odontoma composto e complexo juntos. Independentemente da variante, nota-se que o Odontoma é quase sempre indolente, porém requer cuidados de remoção precoce devido à possibilidade de crescimento, de desenvolvimento de cistos e comprometimento de estruturas adjacentes devido a sua localização e possibilidade de crescimento (AU)

The present work illustrates and discusses this disease that represents the most common odontogenic tumor in clinical practice, the Odontoma. However, an unusual variation of the same is included here in the literature, char-acterized by the exams as a form of compound-complex odontoma additionally causing dentigerous cyst formation and dental impaction. The unusual case occurred in a 21-year-old woman, complaining of missing the tooth 23. The details of the exams allowed the visualization of compound and complex areas in the lesion, cystic formation and dental impaction. The histopathological findings confirmed the diagnosis of the Odontoma, and the interpreta-tion with the set of other exams led to the final diagnosis of Compound-complex odontoma with dentigerous cyst. The present case highlights the need for early removal of Odontoma due to the possibility of developing cysts, compromising adjacent structures, in addition to its growth potential already reported in the literature (AU)

Ki-67 protein predicts survival in oral squamous carcinoma cells: an immunohistochemical study

Abstract The aim of this study was to identify the expression of Ki-67 and MCM3 in oral squamous cell carcinoma (OSCC) as well as to address the correlation with patient survival and clinical features. Samples were collected from 51 patients with OSCC who presented for follow-up. Immunohistochemical expression of Ki-67 and MCM3 in all groups was performed. The scoring system was previous published by Tsurutani in 2005. We used Kappa index to evaluate observers agreement degree. The associations between protein expression and clinical variables were examined for statistical significance using the chi-squared test. The overall survival rates were estimated by the Kaplan-Meier method and the relationship between protein expression and survival was compared using the log-rank test (p < 0.05). The overall survival time for a patient with positive immunostaining for Ki-67 is shorter than for a patient with negative immunostaining, (log-rank test, p = 0.00882). Patients with tumor size T3 and T4 showed a statistically significant relationship with Ki-67 immunoexpression (log-rank test, p = 0.0174). The relationship between Ki-67 expression and the relation between age, gender, smoking, tumor site, lymph node metastasis and disease stage was not significant. The examiners agreement degree by Kappa presented p value < 0.05. There was not a significant correlation when we evaluated MCM3 expression regarding clinical characteristics and survival rate. From these results, the present study suggests that positive Ki-67 expression found in OSCC patients may contribute to predict the survival in OSCC samples, as well as the relation between the protein and the tumor size.

Uso de inibidores de Histona Deacetilase como estratégia terapêutica para sensibilizar células-tronco tumorais a quimioterapia: uma nova visão terapêutica sobre carcinomas mucoepidermoide bucais / Sensitizing Mucoepidermoid Carcinomas to chemotherapy by disrupting the population of Cancer Stem Cells using HDAC inhibitors

Carcinoma mucoepidermóide (CME) é o tumor maligno de glândulas salivares mais comum, representando cerca de 30% dos tumores malignos. O tratamento do CME é a ressecção cirúrgica com eventual radioterapia. Assim, o tratamento do CME pode levar a varias complicações estéticas e funcionais. A quimioterapia tem sido utilizadas apenas em casos recorrentes ou com metástases à distancia. Vários relatos na literatura tem mostrado que o tratamento com drogas isoladas ou combinadas possuem uma resposta insatisfatória e de curta duração em grande parte devido a aquisição de resistência a quimioterapia. Recentemente, a quimiorresistência tem sido relacionada com a presença de Células-Tronco Tumorais (CTT). Essa resistência tem sido associada ao fato de que as essa células são quiescentes e possuem altos níveis de proteínas associadas ao reparo do DNA e baixos níveis das proteínas que levam a apoptose. Recentemente mostrou-se que a resistência a quimioterapia tem sido relacionada com modificações de histonas, uma vez que as células quimiorresistentes possuem núcleo pequeno e baixos níveis de acetilação de histonas, adicionalmente as células sensíveis são relacionadas com núcleo aumentado. O objetivo desse estudo foi avaliar os efeitos do tratamento com IHDAC e cisplatina sobre a população de CTT de CME...

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary tumor compromising about 30% of all salivary malignances. Managing MEC patients remain challenging especially due to the heterogeneous response of tumor cells to available therapy. For this reason clinical outcome remains unpredictable. Current treatment of MEC encompasses surgical resection with eventual adjuvant radiotherapy, which frequently leads to functional and aesthetic complications. The use of chemotherapy is often reserved for recurrent and metastatic tumors. Administration of single-agent or combination therapy has showed activity, however overall response rates are unsatisfactory and of short duration. Emerging evidences suggest that the modest response of tumor cells to therapy resulting in high recurrence rates and poor survival, are associated with the presence of cancer stem cells (CSC). Quiescence of CSC is achieved by the reduced levels of transcription in a process that requires tight folding of DNA driven by core histone proteins. Changes in DNA folding are responsible for different cellular phenotypes mediated by a cell type-specific chromatin organization. Of interest, we also found that acetylation of HNSCC tumor histones driven by histone deacetylase (HDAC) inhibitors abrogate tumor resistance to chemotherapy. We investigate the effects of HDACi and cisplatin in the population of CSCs of MEC...