TWIST and p-Akt immunoexpression in normal oral epithelium, oral dysplasia and in oral squamous cell carcinoma.

OBJECTIVES: The aim of this study was to evaluate the immunoexpression of TWIST and p-Akt proteins in oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC), correlating their expressions with the histological features of the lesions. STUDY DESIGN: Immunohistochemical studies were carried out on 10 normal oral epithelium, 30 OL and 20 OSCC formalin-fixed, paraffin-embedded tissue samples. Immunoperoxidase reactions for TWIST and p-Akt proteins were applied on the specimens and the positivity of the reactions was calculated for 1000 epithelial cells. RESULTS: Kruskal-Wallis and Dunn's post tests revealed a significant difference in TWIST and p- Akt immunoexpression among normal oral mucosa, OL and OSCC. In addition, a significant positive correlation was found between TWIST and p-Akt expressions according to the Pearson's correlation test. CONCLUSIONS: The results obtained in the current study suggest that TWIST and p-Akt may participate of the multi-step process of oral carcinogenesis since its early stages.

Immunoexpression of Ki67, proliferative cell nuclear antigen, and Bcl-2 proteins in a case of ameloblastic fibrosarcoma.

Ameloblastic fibrosarcoma (AFS), regarded as the malignant counterpart of the benign ameloblastic fibroma, is an extremely rare odontogenic neoplasm with only 68 cases reported in the English literature up to 2009. It is composed of a benign odontogenic epithelium, resembling that of ameloblastoma, and a malignant mesenchymal part exhibiting features of fibrosarcoma. Due to the rarity of the lesion, little is known about its molecular pathogenesis; therefore, in the current study, we sought to evaluate the immunoexpression of Ki67, proliferative cell nuclear antigen, and Bcl-2 proteins in AFS, comparing the results obtained with its benign counterpart, as well as to report a new case of this rare entity affecting a 19-year-old female patient. The results obtained revealed that all the proteins evaluated were overexpressed in the malignant mesenchymal portion of AFS if compared with ameloblastic fibroma, suggesting that nuclear proliferative factors such as Ki67 and proliferative cell nuclear antigen, in association to histopathologic features, may be useful markers for identifying the malignancy and that, despite the lack of molecular analysis in the case reported, Bcl-2 alteration may play a role in AFS pathogenesis.

Expression of CD90 and P75NTR stem cell markers in ameloblastomas: a possible role in their biological behavior.

Multicystic and unicystic ameloblastomas are benign odontogenic tumors that present distinct biological behavior. The investigation of stem cells has become an important branch of tumor biology, with several studies addressing the possible role of these cells in tumor growth, angiogenesis, progression, infiltration and invasiveness. This study evaluated the immunohistochemical expression of CD90(Thy-1) and P75NTR stem cell markers in multicystic and unicystic ameloblastomas. Seventeen (17) samples of ameloblastomas (multicystic, n = 10; unicystic, n = 7) were submitted to immunohistochemical reactions and graded semi-quantitatively. The Kolmogorov-Smirnov test was used to verify possible differences in CD90 and P75NTR expressions between multicystic and unicystic ameloblastomas (p < 0.05). CD90 immunostaining was observed in all multicystic ameloblastoma specimens (n = 10), in the cytoplasm of the fibroblasts and vascular endothelial cells of the tumor stroma, near the neoplastic odontogenic epithelia. The staining of stromal CD90 was significantly higher in multicystic than in unicystic ameloblastomas (p = 0.003). Nuclear P75NTR immunostaining was observed in all ameloblastoma specimens. A significant difference was seen in the epithelial staining of P75NTR between multicystic and unicystic types (p = 0.007). The increased expression of CD90 and P75NTR found in multicystic ameloblastomas suggests a behavioral biological difference between multicystic and unicystic ameloblastomas, as well as a difference in ameloblastoma development.

Expression of CD90 and P75NTR stem cell markers in ameloblastomas: a possible role in their biological behavior

Abstract Multicystic and unicystic ameloblastomas are benign odontogenic tumors that present distinct biological behavior. The investigation of stem cells has become an important branch of tumor biology, with several studies addressing the possible role of these cells in tumor growth, angiogenesis, progression, infiltration and invasiveness. This study evaluated the immunohistochemical expression of CD90(Thy-1) and P75NTR stem cell markers in multicystic and unicystic ameloblastomas. Seventeen (17) samples of ameloblastomas (multicystic, n = 10; unicystic, n = 7) were submitted to immunohistochemical reactions and graded semi-quantitatively. The Kolmogorov-Smirnov test was used to verify possible differences in CD90 and P75NTR expressions between multicystic and unicystic ameloblastomas (p < 0.05). CD90 immunostaining was observed in all multicystic ameloblastoma specimens (n = 10), in the cytoplasm of the fibroblasts and vascular endothelial cells of the tumor stroma, near the neoplastic odontogenic epithelia. The staining of stromal CD90 was significantly higher in multicystic than in unicystic ameloblastomas (p = 0.003). Nuclear P75NTR immunostaining was observed in all ameloblastoma specimens. A significant difference was seen in the epithelial staining of P75NTR between multicystic and unicystic types (p = 0.007). The increased expression of CD90 and P75NTR found in multicystic ameloblastomas suggests a behavioral biological difference between multicystic and unicystic ameloblastomas, as well as a difference in ameloblastoma development.

Bilateral dentigerous cyst in a nonsyndromic patient: case report and literature review.

Dentigerous cysts are the most common developmental cysts of the jaws and are associated with impacted teeth. Bilateral dentigerous cysts are rare and typically occur in association with a developmental syndrome. The occurrence of bilateral dentigerous cysts in the absence of a developmental syndrome is very rare. The purpose of this paper was to report on a nonsyndromic, 5-year-old boy who presented mandibular bilateral dentigerous cysts.

Prevalência do prolongamento do processo estilóide e/ou calcificação do ligamento estilo-hióideo em radiografias panorâmicas / Prevalence of elongated styloid process and/or ossified stylohyoid ligament in panoramic radiographs

OBJETIVO: Avaliar a prevalência do prolongamento do processo estilóide e/ou calcificação do ligamento estilo-hióideo em uma amostra de 2.600 radiografias panorâmicas. MÉTODOS: As radiografias foram avaliadas por um único examinador e foram consideradas imagens compatíveis com a alteração aquelas em que o processo estilóide do osso temporal ultrapassasse em mais de 1cm (medido sobre a radiografia panorâmica) a borda mais inferior da cartilagem do lóbulo da orelha, e aquelas em que o ligamento estilo-hióideo se apresentasse radiopaco. RESULTADOS: Cento e quarenta e seis radiografias (5,61 por cento) apresentaram as alterações em estudo. Os resultados mostraram que o alongamento do processo estilóide e/ou calcificação do ligamento estilo-hióideo não foram achados. Houve maior incidência do prolongamento do processo estilóide e/ou calcificação do ligamento estilo-hióideo no sexo feminino (63 por cento), sendo este na maioria dos casos bilateralmente (84 por cento) e apresentando uma maior prevalência na faixa etária de 11 a 40 anos. CONCLUSÃO: Pôde-se concluir que houve maior prevalência da alteração no sexo feminino e a maioria dos casos ocorreu bilateralmente..

OBJECTIVE: Access the prevalence of elongated styloid process and/or ossified stylohyoid ligament in 2.600 panoramic radiographs. METHODS: A total of 2600 radiographs were examined by the same examiner. Images where the styloid process of the temporal bone extended beyond the lower edge of the cartilage of the ear lobe by more than 1 cm (measured on the panoramic radiograph) and those where the stylohyoid ligament was radiopaque were counted. RESULTS: One hundred forty-six (5.61 percent) radiographs presented the abovementioned characteristics. The results showed that elongation of the styloid process and/or stylohyoid ligament ossification were not uncommon events. These changes were more common in females (63 percent) and were usually bilateral (84 percent). They were also more common in the 11-40 years age range. CONCLUSION: Prolongation of the styloid process and/or ossification of the stylohyoid ligament were significantly more common in females. The rates at which the sides were affected were also statistically different.

Expressão imunoistoquímica das citoqueratinas 7 e 8 em carcinomas epidermóides de assoalho bucal / Citokeratin 7 and Citokeratin 8 immunohistochemical expression in Oral Squamous Cell Carcinoma of the floor of the mouth

Objetivo: Verificar a presença da expressão imunoistoquímica das Citoqueratinas (CKs) 7 e 8 nas células do Carcinoma epidermóide localizado em assoalho bucal (CEAB), estabelecendo a especulação de que essa neoplasia tem origem no epitélio de transição entre o ducto excretor da glândula salivar e a mucosa oral de superfície. Métodos: Noventa e dois casos de CEAB foram avaliados através da técnica imunoistoquímica da streptavidina/biotina, utilizando-se anticorpos monoclonais anti-CKs 7 e 8. Resultados: Setenta e oito casos (84,78%) mostraram positividade para as CKs estudadas. Quarenta e cinco casos (48,9%) mostraram positividade para CK7 e sessenta seis casos (71,7%) para CK8. Conclusão: Houve uma intensa marcação celular das CKs estudadas. Os resultados encontrados indicam a participação do epitélio de transição entre os ductos excretores das glândulas salivares e a mucosa bucal de revestimento, na gênese dos carcinomas epidermóides nessa localização...

Objetive: The aim of this study is to verify the presence of Citokeratin 7 (CK7) and Citokeratin 8 (CK8) positive cells of OSCC of the floor of the mouth establishing a speculation if this neoplasia has origin in excretory salivary duct epithelia transition to floor of the mouth mucosa. Methods: Ninety two cases of OSCC of the floor of the mouth were evaluated by straptavidin/biotin complex immunohistochemical technique and anti-CK7 and anti-CK8 monoclonal antibodies were used. Results: Seventy eight cases (84,78%) showed positive for one of the CKs; Forty five cases (48,9%) showed positive for CK7 and sixty six cases (71,7%) showed positive for CK8. Conclusions: There is a high and significantly incidence of the immuno expression of this citokeratins. These results suggest that the excretory salivary duct epithelia transition to floor of the mouth mucosa participates on the genesis of the OSCC in this location...