Transcriptional profiles of SHH pathway genes in keratocystic odontogenic tumor and ameloblastoma.

BACKGROUND: Sonic hedgehog (SHH) pathway activation has been identified as a key factor in the development of many types of tumors, including odontogenic tumors. Our study examined the expression of genes in the SHH pathway to characterize their roles in the pathogenesis of keratocystic odontogenic tumors (KOT) and ameloblastomas (AB). METHODS: We quantified the expression of SHH, SMO, PTCH1, SUFU, GLI1, CCND1, and BCL2 genes by qPCR in a total of 23 KOT, 11 AB, and three non-neoplastic oral mucosa (NNM). We also measured the expression of proteins related to this pathway (CCND1 and BCL2) by immunohistochemistry. RESULTS: We observed overexpression of SMO, PTCH1, GLI1, and CCND1 genes in both KOT (23/23) and AB (11/11). However, we did not detect expression of the SHH gene in 21/23 KOT and 10/11 AB tumors. Low levels of the SUFU gene were expressed in KOT (P = 0.0199) and AB (P = 0.0127) relative to the NNM. Recurrent KOT exhibited high levels of SMO (P = 0.035), PTCH1 (P = 0.048), CCND1 (P = 0.048), and BCL2 (P = 0.045) transcripts. Using immunolabeling of CCND1, we observed no statistical difference between primary and recurrent KOT (P = 0.8815), sporadic and NBCCS-KOT (P = 0.7688), and unicystic and solid AB (P = 0.7521). CONCLUSIONS: Overexpression of upstream (PTCH1 and SMO) and downstream (GLI1, CCND1 and BCL2) genes in the SHH pathway leads to the constitutive activation of this pathway in KOT and AB and may suggest a mechanism for the development of these types of tumors.

Immunohistochemistry assessment of Langerhans cells and microvascular density in oral squamous cell carcinomas / Avaliação imuno-histoquímica de células de Langerhans e densidade microvascular em carcinoma oral de células escamosas

The aim of this study was to assess and correlate microvascular density (MVD) and the quantity of Langerhans cells (LC) present in oral squamous cell carcinoma (OSCC), well as the correlation between this microvascular density and number of Langerhans cells (LCs) with the intensity of the infiltrate, the histologic grading and staging, according to the TNM system. Twenty-three paraffin-embedded blocks of SCC lesions were analyzed using the immunohistochemical technique in which the two anti-CD1a and anti-CD207 markers were used to quantify the Langerhans cells and the CD34 marker to assess MVD. Immunostaining for CD1a, CD207 and CD34 was observed in 100% of the cases analyzed, showing a statistically significant association (p = 0.0001, Fisher’s test). No statistical correlation between MVD and LC or between immunostainings and histological grading of malignancy were found. However, immunostaining for CD1a and CD207 showed a statistically significant correlation (p value = 0.001, Spearman test) and a positive correlation was found between MVD and lymph node involvement. The LCs and MVD seem to involved in immunopathogenesis of oral carcinoma, although no statistically significant correlation was found between these two findings

O objetivo deste estudo foi avaliar e correlacionar a densidade microvascular (MVD) e a quantidade de células de Langerhans (LC) presente no carcinoma epidermoide de boca (CEB), bem como a correlação entre esta densidade microvascular e número das células de Langerhans (CL), com a intensidade do infiltrado, a classificação histológica e de teste, de acordo com o sistema TNM. Vinte e três blocos de parafina-encaixados de lesães SCC foram analisados utilizando a técnica de imuno-histoquímica em que os dois marcadores anti-CD1a e anti-CD207 foram usados para quantificar as células de Langerhans e o marcador CD34 para avaliar MVD. A imunocoloração para CD1a, CD207 e CD34 foi observada em 100% dos casos analisados, demonstrando uma associação estatisticamente significativa (p = 0,0001, teste de Fisher). Não houve correlação estatística entre MVD e LC ou entre imunomarcações e gradação histológica de malignidade foram encontrados. No entanto, a imunocoloração para CD1a e CD207 mostraram uma correlação estatisticamente significativa (p = 0,001, teste de Spearman) e foi encontrada uma correlação positiva entre MVD e comprometimento de linfonodos. O LCs e MVD parecem envolvidos em imunopatogênese de carcinoma oral, embora não foi encontrada correlação estatisticamente significativa entre estes dois resultados.

Tumor-infiltrating macrophage and microvessel density in oral squamous cell carcinoma.

Tumor-associated macrophages (TAM) are the main cellular component in stroma of many tumors and participate in tumor angiogenesis. The aim of present study was to compare the microvascular density (MVD) and infiltrating macrophage density (IMD) in oral squamous cell carcinomas (OSCCs) with different histological grades. A histomorphometric analysis was performed after immunohistochemistry using antibodies such as von-Willebrand factor and CD68. A significant difference in MVD was found between well and moderately differentiated OSCCs (p<0.05). TAM were largely present in all studied tumors and the IMD was not different among OSCCs with different histological grades (p=0.381). Significant correlation between MVD and IMD was not observed (p=0.870). In conclusion, these results suggest that TAM and angiogenesis have an influence at different histological grades of OSCC. However, the lack of correlation between MVD and IMD could suggest that angiogenesis does not depend on the number of macrophages present in OSCC, but their predominant phenotype. Further studies involving distinct phenotypes of macrophages should be done to better understand the influence of TAM on the tumor angiogenesis.

Tumor-Infiltrating Macrophage and Microvessel Density in Oral Squamous Cell Carcinoma

Tumor-associated macrophages (TAM) are the main cellular component in stroma of many tumors and participate in tumor angiogenesis. The aim of present study was to compare the microvascular density (MVD) and infiltrating macrophage density (IMD) in oral squamous cell carcinomas (OSCCs) with different histological grades. A histomorphometric analysis was performed after immunohistochemistry using antibodies such as von-Willebrand factor and CD68. A significant difference in MVD was found between well and moderately differentiated OSCCs (p<0.05). TAM were largely present in all studied tumors and the IMD was not different among OSCCs with different histological grades (p=0.381). Significant correlation between MVD and IMD was not observed (p=0.870). In conclusion, these results suggest that TAM and angiogenesis have an influence at different histological grades of OSCC. However, the lack of correlation between MVD and IMD could suggest that angiogenesis does not depend on the number of macrophages present in OSCC, but their predominant phenotype. Further studies involving distinct phenotypes of macrophages should be done to better understand the influence of TAM on the tumor angiogenesis.

Macrófagos associados a tumores (MAT) representam o componente principal do estroma de muitos tumores, além de participar da angiogênese tumoral. Este estudo comparou a microdensidade vascular (MDV) e densidade de macrófagos infiltrando o tumor (DMIT) em carcinoma escamocelular da boca (CEC) com diferentes graus histológicos de malignidade. Análise histomorfométrica foi empregada após técnica imuno-histoquímica para os anticorpos fator von-Willebrand e CD68. Uma diferença significante entre MDV e carcinomas bem e moderadamente diferenciados foi observada (p<0,05). MAT estavam fortemente presentes em todos os tumores estudados e a DMIT não foi diferente entre os diferentes graus histológicos de malignidade do CEC (p=0,381). Correlação significante entre MDV e DMIT não foi observada (p=0,870). Em conclusão, os resultados desse estudo sugerem a influência de MAT e angiogênese nos diferentes graus histológicos de malignidade do CEC. Entretanto, a ausência de correlação entre MDV e DMIT sugere que a angiogênese não depende do número de macrófagos presentes neste tipo de câncer, mas do fenótipo predominante. Outros estudos devem ser realizados a fim de contribuir para melhor compreensão da participação de MAT na angiogênese tumoral.

CD1a-positive Langerhans cells and their relationship with E-cadherin in ameloblastomas and keratocystic odontogenic tumors.

BACKGROUND: Ameloblastomas and keratocystic odontogenic tumors (KOTs) are lesions that are characterized by locally invasive growth and cause extensive bone destruction. In addition, it is known that E-cadherin influences the adhesion of Langerhans cells (LCs) to keratinocytes. OBJECTIVE AND METHODS: The aim of this study was to investigate, using immunohistochemistry, the distribution of CD1a-positive cells in ameloblastomas and KOTs and their relationship with E-cadherin, in comparison to calcifying cystic odontogenic tumor (CCOT). RESULTS: The CD1a-positive LCs were observed in 11 ameloblastomas and KOTs. All of the cases of CCOT showed CD1a-positive LCs and a significant difference was found when this tumor was compared with ameloblastomas (P < 0.05, Mann-Whitney test). A statistically significant difference was also noted when comparing CD1a-positive LCs between CCOTs and KOTs (P < 0.05, Mann-Whitney test). Lower expression of E-cadherin in ameloblastomas (AMs) in relation to KOTs and CCOTs (P < 0.05, Fisher test) was observed. There was no correlation between E-cadherin and CD1a-positive LCs between all odontogenic tumors that were studied (P > 0.05, Spearman test). CONCLUSION: A quantitative difference of CD1a-positive cells between AMs and KOTs in comparison to CCOTs was observed. This permits to speculate that a depletion of CD1a-positive LCs might influence the local invasiveness of ameloblastomas and KOTs. Furthermore, it is suggested that E-cadherin mediates cell adhesion in these tumors.

Effects of imiquimod and low-intensity laser (λ660 nm) in chemically induced oral carcinomas in hamster buccal pouch mucosa.

Squamous cell carcinoma (SCC) is the most common neoplasm of the oral cavity. It is aggressive, highly proliferative, and metastatic. This study aimed to evaluate the effect of LLLT and imiquimod on DMBA chemically induced lesions on the oral mucosa of hamsters. SCCs were induced on 25 hamsters. Animals of G1 (control 1) were killed and the presence of tumors confirmed; G2 (control 2) suffered no interventions for additional 4 weeks; animals of G3 (laser treatment) were irradiated (λ660 nm, 50 mW, CW, Ø=3 mm, 0.07 cm(2), 714.2 mW/cm(2), 133 s, 95 J/cm(2), 6.65 J) at every other day for 4 weeks; animals of G4 (imiquimod treatment) received 5 % imiquimod three times a week for 4 weeks; and animals of G5 (imiquimod and laser treatment) received both treatments for the same period. Samples were taken and underwent histological analysis by light microscopy and were investigated using immunohistochemistry for S-100(+) dendritic cells. In G1, G2, and G3, the evaluations showed malignant tumors and the absence of S-100(+) dendritic cells in the tumor stroma. In G4, 60 % of the animals had no malignant tumors, and S-100(+) dendritic cells were present in the stroma of the tumors as well as dysplasia. In G5, 40 % of the animals presented SCC, with scarce or no S-100(+) dendritic cells. The imiquimod treatment played a direct effect on SCC, demonstrated by the increased number of S-100(+) dendritic cells, which could suggest an important role of immune surveillance against neoplastic proliferation. Furthermore, its association with laser needs to be further investigated.

Density of mast cells and microvessels in minor salivary gland tumors.

The aim of this study was to investigate the density of mast cells and microvessels in minor salivary gland tumors. Forty-one cases of minor salivary gland tumors (pleomorphic adenoma, n = 10; adenoid cystic carcinoma, n = 11; mucoepidermoid carcinoma, n = 10; and polymorphous low-grade adenocarcinoma) were investigated using immunohistochemistry for mast cell tryptase and von-Willebrand factor. Density of mast cells was higher in mucoepidermoid carcinoma; however, no differences in the number of these cells were observed between the different types of tumors (p > 0.05). The number of mast cells was higher in periparenchymal areas in all tumors, but the difference was not significant (p > 0.05). Mucoepidermoid carcinoma showed the largest number of periparenchymal mast cells, whereas pleomorphic adenomas showed the smallest number of intraparenchymal mast cells (p > 0.05). The highest microvessel density was observed in mucoepidermoid carcinomas, being this difference statistically significant when mucoepidermoid carcinoma was compared to pleomorphic adenoma (p = 0.0034) and polymorphous low-grade adenocarcinoma (p = 0.004). Microvessel density was significantly higher in adenoid cystic carcinoma when compared to pleomorphic adenoma (p = 0.0406) and polymorphous low-grade adenocarcinoma (p = 0.0123). Comparison of mast cells and microvessel densities showed no significant difference between tumors. A quantitative difference in mast cells and microvessels was observed, particularly in mucoepidermoid carcinoma, a finding supporting the aggressive behavior of malignant salivary gland tumors without myoepithelial differentiation. Further studies are needed to determine the role of mast cells in angiogenesis, as well as in the development and biological behavior of these tumors.

Elastin accumulation in actinic cheilitis with different degrees of epithelial dysplasia / Acumulación de elastina en queilitis actínica con diferentes grados de displasia epitelial

The extracellular matrix (ECM) plays an important role in the regulation of biological events such as the development of cell migration, proliferation and differentiation. Chronic sun exposure causes changes present in the ECM of actinic cheilitis (AC), a premalignant lesion of the lower lip which helps to understand the carcinogenesis of the lip. This study aimed to investigate elastin, the main component of solar elastosis alternating current in an attempt to establish the relationship between this protein and ECM in epithelial dysplasia. Paraffin embedded tissue sections of the lesions of 35 cases of AC were analyzed by immunohistochemistry for elastin, and became the association with the degree of epithelial dysplasia and age. Highest scores of elastin (+3) was predominant in 45.7 percent of cases of AC, especially in cases of severe dysplasia (n = 3). When comparing the scores of elastin between the different grades of epithelial dysplasia showed no significant difference (P> 0.05, Kruskal-Wallis). This study was not able to demonstrate the influence of elastin on the severity of epithelial dysplasia in AC. Additional studies on other ECM proteins must be conducted in an attempt to better understand the mechanism of malignant progression of the AC.

La matriz extracelular (MEC) juega un papel importante en la regulación de los eventos biológicos, tales como, el desarrollo de la migración celular, proliferación y diferenciación. La exposición solar crónica provoca cambios presentes en la MRC de la queilitis actínica (QA), una lesión premaligna del labio inferior que contribuye a entender la carcinogénesis del labio. Este estudio tuvo como objetivo investigar la elastina, el componente principal de la elastosis solar en corriente alterna en un intento de establecer la relación entre esta proteína y la MEC en displasia epitelial. Se incluyeron en parafina cortes de tejido de las lesiones de 35 casos de QC fueron analizadas mediante técnicas de inmunohistoquímica para elastina, y se hizo la asociación con los grados de displasia epitelial y la edad. La más alta puntuación de la elastina (+3) fue predominante en el 45,7 por ciento de los casos de QA, especialmente en los casos de displasia severa (n = 3). Al comparar las puntuaciones de elastina entre los diferentes grados de displasia epitelial, no mostró diferencia significativa (P> 0,05, Kruskall-Wallis). Este estudio no fue capaz de demostrar la influencia de la elastina sobre gravedad de la displasia epitelial en QA. Estudios adicionales sobre otras proteínas de la MEC deben llevarse a cabo en un intento por comprender mejor el mecanismo de progresión maligna de la QC.

Queilite actínica: um estudo de 35 casos com destaque para os aspectos morfológicos / Actinic cheilitis: a study of 35 cases highlighting their morphological features

A queilite actínica (QA) é uma alteração crônica, pré-maligna, resultante da exposição solar frequente e prolongada. Afeta principalmente o lábio inferior de pessoas idosas, do sexo masculino e de pelo clara. Sabendo-se que a QA é influenciada pela radiação solar e que ao nosso conhecimento não existem dados clínicos e histológicos dessa lesão no Nordeste do Brasil, o presente estudo analisou uma série de 35 casos de QA na população dessa região brasileira. As lâminas referentes a cada caso foram coradas pela técnica da hematoxilina e eosina (HE) e analisadas por microscopia de luz, sendo descritos os aspectos morfológicos das lesões. Os dados clínicos foram obtidos a partir das fichas de solicitação do exame anatomopatológico. Dos 35 caos de nossa amostra, 60 por cento representou o sexo masculino. A idade média foi de 54,6 anos. A maioria dos pacientes era leucoderma. As lesões de QA caracterizavam-se por epitélio pavimentoso estratificado exibindo graus variáveis de queratinização. Elastose solar esteve presente em todos os casos. Quanto ao grau de displasia, 17 casos apresentavam displasia discreta, 13 eram de displasia moderada e 5 eram representados por displasia severa. Embora os casos desse estudo apresentassem displasia epitelial, estas não foram suficientemente severas para gerar uma neoplasia invasiva. Contudo, é importante que estudos dessa natureza sejam realizados em outras regiões do país para que políticas públicas sejam estabelecidas para evitar o aparecimento e malignização dessas lesões.

Distribution of mast cells in benign odontogenic tumors.

The aim of this study was to investigate the presence of mast cells in a series of odontogenic tumors. Forty-five cases of odontogenic tumors were investigated using immunohistochemistry for mast cell triptase, and differences between groups were statistically evaluated. Mast cells were present in 96% of odontogenic tumors. Mast cells present in solid ameloblastoma were observed in the tumor stroma surrounding more solid and follicular epithelial islands, with or without squamous metaplasia. The odontogenic mixoma showed few mast cells. In odontogenic tumors with a cystic structure, the mast cells were distributed throughout all areas of the lesions, mainly in keratocystic odontogenic tumor. In addition, the total density of mast cells between all odontogenic tumors showed no significant difference (p > 0.05). A greater mast cells distribution was found in keratocystic odontogenic tumor in relation to adenomatoid odontogenic tumor (p < 0.01), and when the unicystic ameloblastoma and keratocistic odontogenic tumor were compared to the odontogenic myxoma (p < 0.05). Syndrome keratocystic odontogenic tumor showed a higher mean of mast cells when compared with the other tumors of the sample. Mast cells values presented by syndrome keratocystic odontogenic tumor were significantly greater than those of the sporadic keratocystic odontogenic tumor that were not associated with the syndrome (p = 0.03). Mast cells are probably one of the major components of the stromal scaffold in odontogenic tumors. We found significant differences of mast cells between syndrome nonsyndrome keratocystic odontogenic tumors, although their distribution did not seem to have any influence on the biologic behavior of benign odontogenic tumors.

Immunohistochemical assessment of CD1a-positive Langerhans cells and their relationship with E-cadherin in minor salivary gland tumors.

OBJECTIVE: The aim of this study was to investigate the presence of CD1a-positive Langerhans cells and their relationship with E-cadherin in minor salivary gland tumors. METHODS: Twenty-seven minor salivary gland tumors were investigated using immunohistochemistry for CD1a and E-cadherin. RESULTS: A significant difference regarding the mean density of CD1a-positive Langerhans cells was observed between pleomorphic adenomas and malignant tumors studied (P = 0.001). No CD1a-positive cells were detected in most cases (n = 5) of cystic adenoid carcinomas. CD1a-positive cells were detected in one mucoepidermoid carcinoma case, and six low-grade polymorphous adenocarcinomas cases. Comparison of the mean density of CD1a-positive cells between the three malignant tumors showed no significant difference (P = 0.127). No significant difference was observed in the presence of E-cadherin between tumors (P = 0.73), but it was detected in 24 cases. CONCLUSIONS: The lack of CD1a-positive in malignant salivary gland tumors facilitates the neoplastic development and suggests that these cells might be useful as auxiliary diagnostic and prognostic tool in minor salivary gland tumors. Furthermore, it is suggested that E-cadherin mediates cell adhesion in these tumors although we did not demonstrate significance.

Histopathological study of radicular cysts diagnosed in a Brazilian population.

The aim of this study was to investigate the histopathological features of radicular cysts (RCs) diagnosed in a Brazilian population. Seventy-three cases of RCs, from a total of 1480 biopsies diagnosed between 2001 and 2008 at the Laboratory of Oral Surgical Pathology of the Dental School of the Federal University of Bahia were investigated regarding their histopathological features. Morphological results showed that exocytosis (n = 50), spongiosis (n = 40), acanthosis (n = 28), atrophic epithelium (n = 27) and apoptotic bodies (n = 21) were the most common findings. Other morphological findings included: foamy macrophages (n = 10), Russell's bodies (n = 7), cholesterol crystals (n = 7) and glandular-like odontogenic epithelial rests (n = 1). Evidence of exogenous material was seen in 16 samples. It was concluded that the clinical and histopathological findings observed in Brazilian patients were comparable with those described for other populations.

Keratocystic odontogenic tumour: an experience in the Northeast of Brazil.

INTRODUCTION: Keratocystic odontogenic tumours raise particular interest, because of their high recurrence rate and association with nevoid basal cell carcinoma syndrome. OBJECTIVE: To analyze the clinical and histopathological features of all cases diagnosed as keratocystic odontogenic tumour in a Brazilian population. METHODS: A total of 64 keratocystic odontogenic tumours, arising in forty-six patients, were evaluated using the following parameters: association with nevoid basal cell carcinoma syndrome, gender, age at first diagnosis, race, anatomical location, symptoms, radiographic features, history of recurrence, association with teeth, and treatment. RESULTS: Keratocystic odontogenic tumours were more frequent among women than men (1:0.84). The mean patient age was 31.5 years (SD: +/- 16.6). Ten tumours (16.4%) involved the maxilla and 51 (83.6%) the mandible. Swelling (n = 12; 46.1%), followed by pain and swelling (n = 4; 15.3%), were most common clinical manifestations. A unilocular radiotransparency with well-defined margins was the main radiographic finding (n = 29; 87.8%). A significant association was observed between the multilocular radiographic pattern and recurrence (p < 0.05, Fisher's Test). Sixty-one (95.3%) tumours were treated by surgical enucleation followed by bone curettage, and the recurrence rate was 13% (n = 6). This study showed that the keratocystic odontogenic tumours relapsed within a mean period of 25-36 months. CONCLUSION: Despite the results of this study being similar to previous reports found in the literature, it provides an important insight about keratocystic odontogenic tumours in a Brazilian population.

Expressão imunoistoquímica das proteínas p53 e MDM2 em carcinoma espinocelular de boca / p53 and MDM2 proteins immunohistochemical expression in oral squamous cell carcinoma

A proposta deste estudo foi avaliar a correlação entre duas proteínas associadas ao ciclo celular com grau histológico de malignidade dos carcinomas orais. Por meio da técnica imunoistoquímica, 30 casos de carcinoma espinocelular de boca foram estudados . Anticorpos monoclonais DO-7 e 1B10, direcionados à p53 e MDM2, respectivamente, foram utilizados. O acúmulo nuclear da proteína p53 foi encontrado em aproximadamente 80% dos carcinomas orais. A proteína MDM2 foi detectada em 90% dos casos. foi observada correlação estatística significante entre ambos os marcadores (p = 0,046), mas não foi encontrada associação significante entre estes e o grau histológico de malignidade. Não foi encontrada correlação entre p53 e MDM2 com o grau histológico de malignidade. Em adição, embora alterações na expressão da p53 representem um evento bem estabelecido em carcinogênese oral, outros mecanismos distintos podem ser considerados, como aqueles envolvendo seu principal regulador, o gene MDM2

Histopathological study of radicular cysts diagnosed in a Brazilian population

The aim of this study was to investigate the histopathological features of radicular cysts (RCs) diagnosed in a Brazilian population. Seventy-three cases of RCs, from a total of 1480 biopsies diagnosed between 2001 and 2008 at the Laboratory of Oral Surgical Pathology of the Dental School of the Federal University of Bahia were investigated regarding their histopathological features. Morphological results showed that exocytosis (n=50), spongiosis (n=40), acanthosis (n=28), atrophic epithelium (n=27) and apoptotic bodies (n=21) were the most common findings. Other morphological findings included: foamy macrophages (n=10), Russell’s bodies (n=7), cholesterol crystals (n=7) and glandular-like odontogenic epithelial rests (n=1). Evidence of exogenous material was seen in 16 samples. It was concluded that the clinical and histopathological findings observed in Brazilian patients were comparable with those described for other populations.

O propósito desse estudo foi investigar os aspectos histopatológicos de cistos radiculares diagnosticados em uma população brasileira. Setenta e três casos de cistos radiculares entre 1480 biópsias diagnosticadas na Faculdade de Odontologia da Universidade Federal da Bahia, entre 2001 e 2008, foram investigados, considerando os seus aspectos histopatológicos. Os resultados morfológicos mostraram que os achados mais comuns foram a exocitose (n=50), espongiose (n=40), acantose (n=28), epitélio atrófico (n=27) e células apoptóticas (n=21). Outros achados encontrados incluíram macrófagos espumosos (n=10), corpúsculos de Russell (n=7), imagens negativas de colesterol (n=7) e restos epiteliais odontogênicos semelhantes à tecido glandular (n=1). Material exógeno foi observado em 16 casos. Concluiu-se que os aspectos histopatológicos e clínicos observados foram comparáveis a outros descritos em outras populações.

Accumulation of CD1a-positive Langerhans cells and mast cells in actinic cheilitis.

LCs and MCs are known to be directly influenced by UV radiation. This study investigated the presence of Langerhans cells (LCs) and mast cells (MCs) in actinic cheilitis (AC) exhibiting epithelial dysplasia (ED). Using immunohistochemistry for CD1a and mast cell tryptase, LCs and MCs density was assessed in 35 cases of AC with different degrees of ED. LCs were found in 32 cases of AC whereas MCs were found in all cases. There was an increase in LCs density irrespective of degree of ED when the cases were compared to normal lip mucosa (P = 0.04343). No statistical difference in LCs density was observed regarding the different degrees of dysplasia (P > 0.05). Significant difference in MCs density between mild and moderate dysplasia and normal lip mucosa was found (P < 0.05). No significant correlation between LCs and MCs was seen (P = 0.1258). Although no correlation could be established between LCs and MCs and the different degrees of ED; it is possible that the accumulation of LCs plays an immunostimulatory and protective role in the defense against progression of dysplasia. Further studies are necessary to determine the role of MCs in the development of AC.

Density of Langerhans cells in the keratocystic odontogenic tumor / Densidade das células de Langerhans no tumor odontogênico queratocístico

INTRODUCTION: 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.

INTRODUÇÃO: Tumor odontogênico queratocístico (TOQ) é uma lesão odontogênica de caráter distinto que afeta frequentemente ossos maxilares. Células de Langerhans (CLs) são células dendríticas especializadas, responsáveis pela apresentação de antígenos aos linfócitos T nas superfícies cutânea e mucosa. OBJETIVO: Este estudo analisou a expressão imuno-histoquímica das CLs em lesões de TOQ. MATERIAIS E MÉTODOS: Quinze casos de TOQ foram estudados utilizando o marcador anti-CD1a. RESULTADOS: As CLs foram observadas em todos os 15 casos analisados. Essas células estavam concentradas em áreas de hiperplasia do epitélio cístico, especialmente naquelas que apresentavam alta concentração de células inflamatórias. Em adição, foi encontrada associação significativa entre número de CLs e áreas do epitélio cístico que apresentavam hiperplasia (Mann-Whitney test, p = 0.0223). O formato e a localização dessas células no epitélio dos TOQs foram variáveis. CONCLUSÃO: O menor número de CLs encontrado no revestimento cístico atrófico dos TOQs pode ser atribuído à imunovigilância deficiente e isso pode resultar em comportamento biológico localmente agressivo.

Clinicopathological and demographic characteristics of ameloblastomas in a population from Bahia, Brazil / Características clinicopatológicas e demográficas de ameloblastomas em uma população da Bahia, Brasil

Purpose: The present study aimed to review a series of ameloblastoma cases by observing their clinicopathological and demographic characteristics. The data in this study were compared to previous studies. Methods: Seventy ameloblastoma cases were obtained from the archive of the Surgical Pathology Service of the Dental School of the Federal University of Bahia and were analyzed with regards to age, gender, clinical manifestation, radiographic aspect, anatomical distribution and histological subtype. These data were submitted to statistical analysis. Results: Of the 70 cases, 35 (50%) occurred in males and 35 (50%) in females. Young adults were most affected by tumors. Fifty-six (80%) of all tumor cases occurred in the jaw. The main histological subtype seen was unicystic ameloblastoma, which occurred in 35 cases. The majority of the tumors [n=57 (81.4%)] were treated with radical surgery. The differences in clinical aspects and anatomical distribution were shown to be statistically significant (P<0.001).Conclusion: The clinical-epidemiological profile of the patients in the present study is similar to that in other populations, with unicystic ameloblastoma being the most common histological subtype seen.

Objetivo: O presente estudo se propôs a revisar uma série de casos de ameloblastomas, observando-se as suas características clinicopatológicas e demográficas. Adicionalmente, os dados foram comparados com estudos prévios.Metodologia: Setenta casos de ameloblastomas foram recuperados dos arquivos do serviço de Patologia Cirúrgica da Faculdade de Odontologia da Universidade Federal da Bahia e analisados quanto a idade, sexo, manifestação clínica, aspecto radiográfico, distribuição anatômica e subtipo histológico. Esses dados foram submetidos à análise estatística.Resultados: Dos 70 casos, 35 (50%) acometeram o sexo masculino e 35 (50%) o sexo feminino. Os adultos jovens foram os mais afetados pelos tumores. A mandíbula foi o sítio preferencial, correspondendo a 56 casos (80%) do total dos tumores analisados. O principal subtipo histológico encontrado foi o ameloblastoma unicístico, que acorreu em 35 casos. A maioria dos tumores [n=57 (81,4%)] foi tratada cirurgicamente de forma radical. Dados em relação ao aspecto clínico e distribuição anatômica apresentaram-se estatisticamente significantes (P<0,001). Conclusão: O perfil clínico- epidemiológico dos pacientes do presente estudo é similar ao de outras populações, sendo que o ameloblastoma unicístico é o subtipo histológico mais comum em nossa população.