Abstract Lower lip squamous cell carcinomas (LLSCC) could be associated with a previous history of potentially malignant oral diseases (PMOD), especially actinic cheilitis (AC), with high sun exposure being a well-described risk factor. Immune evasion mechanisms, such as the PD-1/PD-L1 (programmed cell death protein 1/programmed death-ligand 1) pathway has been gaining prominence since immunotherapy with immune checkpoint inhibitors showed a positive effect on the survival of patients with different types of neoplasms. Concomitant with the characterization of the tumor microenvironment, the expression of either or both PD-1 and PD-L1 molecules may estimate mutual relations of progression or regression of the carcinoma and prognostic values of the patient. Objective: Considering the importance of tumor microenvironment characterization, this study aims to determine the immunoexpression of PD-L1 and correlate with the frequency of CD4+ and CD8+ cells in AC and LLSCC lesions and with tumor-infiltrating lymphocytes (TILs) in LLSCC and its relationship with histopathological characteristics. Methodology: This sample includes 33 cases of AC and 17 cases of LLSCC. The cases were submitted to histopathological analysis and to CD4+, CD8+, and PD-L1+ cell determination by immunohistochemistry. Results: There was a significant difference among the frequencies of CD4+, CD8+, and PD-L1+ cells between AC and LSCC cases, higher in the last group. Moreover, histopathological and atypical changes in AC and LLSCC were correlated with the frequencies of PD-L1+, CD4+, and CD8+ cells. In AC, PD-L1+ cases had a low frequency of CD4+ cells, but on the other hand, PD-L1+ cases of LLSCC had a higher frequency of CD4+ and CD8+ cells. Conclusion: Therefore, the PD-L1 molecule may be a potential escape route for the immune response in oral lesions, but the mechanisms differ between AC and LLSCC. Future studies related to immune evasion and immunotherapy in oral lesions should consider the analysis of inflammatory infiltrate and TILs.

This study aimed to compare the effectiveness of 0.12% chlorhexidine alone and 0.12% chlorhexidine in combination with toothbrushing to prevent ventilator-associated pneumonia (VAP) in mechanically ventilated patients. The Embase, Latin American and Caribbean Health Science Literature, PubMed, Scientific Electronic Library Online, Scopus, LIVIVO, Web of Science, Cochrane Library, OpenThesis, and Open Access Thesis and Dissertations databases were used. Only randomized controlled trials without restrictions on the year or language of publication were included. Two reviewers assessed the risk of bias using the Joanna Briggs Institute Critical Appraisal Tool. A meta-analysis using a random-effects model estimated the combined relative risk (RR). The Grading of Recommendations, Assessment, Development and Evaluations approach was used to assess the certainty of the evidence. Initially, 2,337 studies were identified, of which 4 were considered in the systematic review and 3 in the meta-analysis (total sample: 796 patients). The studies were published between 2009 and 2017. All eligible studies had a low risk of bias. The meta-analysis revealed that the risk of VAP was 24% lower in patients receiving chlorhexidine combined with toothbrushing than in those receiving chlorhexidine alone (RR: 0.76; 95% confidence interval: 0.55-1.06), with moderate certainty of evidence and without statistical significance. In conclusion, considering the limitations of this study, a standard protocol for the prevention of VAP is not yet recommended. More studies with larger sample sizes are needed to draw strong conclusions. However, considering that toothbrushing is a simple intervention, it should be a common practice in mechanically ventilated patients, especially among patients with coronavirus disease.

Oral squamous cell carcinoma (OSCC) is one of the most common malignances. In epithelial-mesenchymal transition (EMT), epithelial cells switch to mesenchymal-like cells exhibiting high mobility. This migratory phenotype is significant during tumor invasion and metastasis.Objective: The aim of this study is to evaluate the expression of the EMT markers E-cadherin, N-cadherin and vimentin in OSCC.Material and Methods : Immunohistochemical detection of E-cadherin, N-cadherin and vimentin was performed on 20 OSCC samples. Differences in the expression of each protein at the invasive front (IF) and in the central/superficial areas (CSA) of the tumor were assessed. Differences in the expression of each protein at the IF of both histologically high- and low-invasive OSCCs were evaluated. Associations among expression of proteins at the IF were assessed. Correlations between the expression levels of each protein at the IF and the tumor stage and clinical nodal status were also evaluated.Results : Reduced expression of E-cadherin was detected in 15 samples (75%). E-cadherin expression was reduced at the IF when compared to the CSA and in high-invasive tumors when compared to low-invasive tumors. All samples were negative for N-cadherin, even though one sample showed an inconspicuous expression. Positive expression of vimentin was observed in 6 samples (30%). Nevertheless, there was no difference in vimentin expression between the IF and the CSA regions or between the low- and high-invasive tumors. Furthermore, no association was observed among protein expression levels at the IF. Finally, no correlations were observed between each protein’s expression levels and tumor stage or clinical nodal status.Conclusions : Reduced E-cadherin expression at the IF and its association with histological invasiveness suggest that this protein is a noteworthy EMT marker in OSCC. Although vimentin was also detected as an EMT marker, its expression was neither limited to the IF nor was it related to histological invasiveness.

Introdução: Implantes dentários têm sido rotineiramente utilizados como excelente alternativa para a reabilitação oral. Pacientes com doenças ósseas displásicas representam um desafio especial para a reabilitação oral com implantes dentários. No entanto, a instalação de implantes em pacientes com displasia cemento-óssea (DCO) tem sido relatada com aparente sucesso.Objetivo: Neste artigo, apresentamos um caso de um paciente com DCO florida em que um implante dentário fora instalado em paciente com lesões da variante florida da displasia cemento-óssea, seguido de insucesso seis meses após a cirurgia. Diante dos achados clínicopatológicos, foi realizada uma análise da pertinência da indicação da instalação do implante dentário em área acometida pela lesão, considerando a natureza displásica da doença, sua patogenia e comportamento biológico.Conclusão: O presente caso é ilustrativo em caracterizar a impertinência da indicação dos procedimentos de implantes dentários em pacientes portadores da DCO, considerando imperativo fornecer informações ao paciente a propósito dos riscos em manipular tecido ósseo portador destas lesões.

Introduction: Osseointegrated dental implants have been routinely used in oral rehabilitation. Patients with dysplastic bone diseases represent a particular challenge for oral rehabilitation with dental implants. Nevertheless, the installation of implants in patients with cemento-osseous dysplasia (COD) has been reported with apparent success.Objective: In this paper, we present a case of a patient with COD in which a dental implant had been installed and lost six months later. In this regard, we analyzed pertinent aspects of the indications for dental implants in patients with COD considering the pathogenesis, dysplastic nature, and behavior of the disease.Conclusion:The present case report illustrates that COD can be considered a limiting factor in the recommendation for a dental implant. Because of this, it is imperative to inform the patient about the risks of surgically manipulating the diseased bone.

Descrevemos um caso excepcional de um odontoma complexo gigante afetando a sínfise mandibular em um menino de nove anos de idade. Devido à sua dimensão esta lesão produziu expansão da cortical óssea, deslocamento dentário e impactação, sinais clínicos muito raramente descritos para odontomas. A lesão foi extirpada cirurgicamente de forma conservadora, utilizando uma abordagem intra-oral com anestesia local. Depois de sete anos de seguimento todos os dentes se encontram erupcionados e o osso mandibular totalmente curado. Devido à sua aparência radiográfica, mista radiolúcida e radiopaca, e seu crescimento expansivo, é imperativo fazer o diagnóstico diferencial de odontoma complexo gigante para outros tumores odontogênicos mistos mais agressivos, como o fibro-odontoma ameloblástico, odotoameloblastoma e tumor odontogênico cístico calcificante. Uma abordagem conservadora parece ser indicada no tratamento dessas lesões.

This paper describes an exceptional case of an enormous complex odontoma affecting the mandibular symphysis of a 9-year-old boy. Because of its dimensions, the lesion produced cortical bone expansion, dental displacement and impactation, which are clinical signs very seldom described for odontomas. The lesion was surgically excised in a conservative way using an intraoral approach with local anesthesia. After 7 years of follow up, all teeth had erupted and the mandibular bone healed totally. Because of its radiographic mixed radiolucent and radiopaque appearance and its expansive growth, it is imperative to make the differential diagnosis of giant complex odontoma for other more aggressive mixed odontogenic tumors, such as ameloblastic fibro-odontoma, odotoameloblastoma and cystic calcified odontogenic tumor. Conservative approach appears to be indicated in the treatment of such lesions.

INTRODUÇÃO: A galectina-3 (GAL3) apresenta importantes papéis na biologia tumoral e recentemente foi mostrada a sua participação na via de sinalização Wnt, translocando a beta-catenina para o núcleo. Expressão alterada de GAL3 e beta-catenina tem sido descrita em cânceres, mas não há estudos avaliando a expressão de ambas em displasias e carcinomas desenvolvidos em modelos de carcinogênese de língua. OBJETIVOS: Estudar a expressão de GAL3 e beta-catenina em lesões displásicas e carcinomas induzidos experimentalmente em língua de camundongos. MATERIAL E MÉTODOS: Vinte camundongos C57BL/6 machos foram desafiados com 4NQO na água de beber por 16 semanas e sacrificados na semana 16 e 32. Após o sacrifício, as línguas foram removidas, processadas, coradas por hematoxilina e eosina (HE) para detecção de displasias e carcinomas. Ensaio imuno-histoquímico foi realizado para determinar o índice de positividade para GAL3 e beta-catenina nessas lesões, bem como uma correlação entre elas em carcinomas. RESULTADOS: O número de camundongos afetados por carcinoma aumentou entre as semanas 16 e 32 (22,2% vs. 88,9%) e o de displasia diminuiu (66,7% vs. 11,1%). Um aumento de células positivas para beta-catenina não membranosa e GAL3 citoplasmática foi observado nas displasias e nos carcinomas, mas essa diferença não foi estatisticamente significativa. No entanto, um aumento estatisticamente significativo de GAL3 nuclear foi observado na evolução de displasia para carcinoma (p = 0,04). Nenhuma correlação foi encontrada entre beta-catenina e GAL3. CONCLUSÃO: Tanto nas displasias quanto nos carcinomas a via de sinalização Wnt está ativa, e o aumento de GAL3 nuclear nos carcinomas sugere um papel na transformação maligna do epitélio lingual.

INTRODUCTION: Galectin-3 plays pivotal role in tumor biology and its participation in Wnt signaling pathway translocating beta-catenin into the nucleus has been recently demonstrated. Altered galectin-3 and beta-catenin expressions have been described in different tumors, however, there are no studies evaluating their expression in dysplasias and carcinomas induced in carcinogenic tongue models. OBJECTIVES: To study galectin-3 and beta-catenin expressions in dysplasias and carcinomas experimentally induced in mouse tongue. METHODS: Twenty C57Bl/6 male mice were treated with 4NQO in their drinking water for 16 weeks and sacrificed at weeks 16 and 32. Tongues were removed, routinely processed, and stained with hematoxylin and eosin to detect dysplasias and carcinomas. An immunohistochemical assay was performed to determine the level of positivity for galectin-3 and beta-catenin in these lesions as well as their correlation in carcinomas. RESULTS: The number of mice affected by carcinomas increased from week 16 to week 32 (22.2% vs. 88.9%) and the number affected by dysplasias decreased (66.7% vs. 11.1%). There was an increase in non-membranous beta-catenin- and cytoplasmic galectin-3-positive cells in dysplasias and carcinomas, although this difference was not statiscally significant. Nonetheless, there was a significant increase of nuclear galectin-3-positive cells in the evolution from dysplasia to carcinoma (p = 0.04). There was no correlation between beta-catenin and galectin-3. CONCLUSION: Wnt signaling pathway is active in both dysplasias and carcinomas and the increase of nuclear galectin-3-positive cells in carcinomas suggests its influence on malignant transformation in the tongue epithelium.

O sarcoma de Ewing é um tumor maligno primário do osso, comumente diagnosticado em adolescentes e adultos jovens. Sua ocorrência na região de cabeça e pescoço não é usual, e geralmente ocorre em maxila ou mandíbula. Após revisão extensiva da literatura, poucos casos foram identificados acometendo pacientes com menos de 5 anos de idade. Nós relatamos um caso raro de SE em uma criança de 4 anos de idade que foi previamente diagnosticada e tratada como abscesso dentoalveolar. Ao exame clínico, uma massa expansiva endurecida e imóvel de 5 cm de diâmetro foi observada no lado esquerdo da mandíbula. O exame radiográfico mostrou lesão radiolúcida, com bordas mal definidas e ampla destruição da tábua óssea vestibular. Microscopicamente, o tumor era composto por células pequenas e arredondadas que exibiam imunorreatividade para CD99, vimentina e pancitoqueratina. O paciente foi submetido à quimioterapia com ifosfamida, carboplatina, e etoposide além de vincristina, ciclofosfamida e doxorrubicina (regime VAC/IE). Entretanto, após o primeiro ciclo da quimioterapia, o paciente foi a óbito por infecção disseminada. Este caso salienta a importância do conhecimento profissional no diagnóstico de tumores malígnas tais como o SE.

Ewing's sarcoma (ES) is a malignancy primarily affecting bone tissue that is commonly diagnosed in adolescents and young adults. Its occurrence in the head and neck region is unusual and generally involves the mandible and maxilla. An extensive review of the literature shows only few cases of the oral ES in patients under the age of 5. This paper reports a rare case of ES of the mandible in a 4-year-old girl, which had been previously misdiagnosed and treated as a dental abscess. In the clinical examination, a hard immobile expansive mass of 5 cm in diameter was observed on the left side of the mandible. Radiographic examination revealed a radiolucent lesion with ill-defined borders and wide vestibular bone plate destruction. Microscopically, the tumor was composed by monotonous small round cells that exhibited immunoreactivity for CD99, vimentin and pancytokeratin. The patient was subjected to multiagent chemotherapy with ifosfamide, carboplatin, etoposide, vincristine, cyclophosfamide and doxorrubycin (VAC/ICE regimen). However, after the first chemotherapeutic cycle, the patient died due to disseminated infection. This case elucidates the importance of professional knowledge of the relevant aspects of malignant lesions such as ES.

The association among clinicopathological features and c-erbB-2 oncoprotein expression was evaluated in twenty-nine cases of intra-oral mucoepidermoid carcinoma (MEC). MEC was prevalent in the female gender (79.3%), tumors were more frequent in ages between 21 and 40 years (48.3%), and the palate was the most commonly affected site (72.4%). Microscopically, 27 cases (93.1%) were classified as low grade of malignancy. The c-erbB-2 expression was considered positive in 9 (31%) cases and no significant association (p>0.05) was found among protein expression and gender ñor between patient age and site or histological grade of the lesión. c-erbB-2 expression in MEC may reflect intrisinc biologic properties of salivary gland neoplasms and may be linked to histogenesis and cellular differentiaton.

Fueron evaluados 29 casos de carcinoma mucoepidermoide intraoral en sus aspectos clínico-patológicos, además de la expresión de la oncoproteina c-erbB-2. El carcinoma mucoepidermoide fue predominante en las mujeres (79,3%), siendo más frecuente en individuos entre 21 y 40 años de edad (48,3%). El paladar fue el sitio más comunmente afectado (72,4%). Microscópicamente, 27 casos (93,1%) fueron clasificados como de baja malignidad. La expresión del c-erbB-2 se consideró positiva en 9 (31%) casos y no fue observada ninguna asociación significativa (p>0,05) entre la expresión de la proteína y género, ni entre la edad de los pacientes y el sitio o el grado histológico de la lesión. La expresión de la c-erbB-2 en el carcinoma mucoepidermoide puede mostrar las propiedades biológicas intrísecas de las neoplasias de las glándulas salivales.

INTRODUÇÃO: A galectina-3 (Gal-3) é uma lectina de mamíferos ligante de resíduos b-galactosídeos. Numerosos estudos têm mostrado que a Gal-3 apresenta importantes papéis na biologia tumoral, atuando em fenômenos como apoptose, metástase e transformação maligna. No entanto, em carcinomas de cabeça e pescoço, a real significância da sua expressão ainda é pouco compreendida. OBJETIVO: O objetivo deste estudo foi avaliar a expressão de Gal-3 em tumores de língua induzidos experimentalmente em camundongos desafiados com o carcinógeno 4-nitroquinolona-1-óxido (4NQO). MATERIAL E MÉTODOS: Quarenta e dois camundongos C57BL/6, machos, foram desafiados com 4NQO na água de beber por 16 semanas e sacrificados em diferentes períodos depois do tratamento. Após o sacrifício, as línguas foram removidas, processadas, coradas por hematoxilina e eosina (HE) e microscopicamente analisadas quanto à presença de carcinoma. Ensaio imuno-histoquímico para detecção do antígeno Gal-3 e análise descritiva da sua expressão nos tumores induzidos foram realizados. RESULTADOS: Ao final do experimento, foram produzidos 15 tumores. No tecido epitelial não-neoplásico, forte imunorreatividade foi observada apenas na camada parabasal. Nas camadas mais superficiais a intensidade de marcação foi mais fraca, e na camada basal variou de ausente a fraca. Todos os carcinomas bem diferenciados exibiram fraca marcação, exceto nas áreas queratinizantes. No único caso de carcinoma pouco diferenciado, forte imunorreatividade para Gal-3 foi observada. CONCLUSÃO: Nossos resultados descritivos mostram que a transformação maligna é acompanhada de redução da intensidade de expressão da Gal-3 e que o aumento da sua expressão com a perda da diferenciação neoplásica sugere a sua vinculação com agressividade tumoral.

BACKGROUND: Galectin-3 (Gal-3) is a b-galactoside-binding mammalian lectin. Numerous studies have demonstrated that Gal-3 plays an important role in tumor biology, acting in some events such as apoptosis, metastasis and malignant transformation. However, in carcinomas of head and neck, the real significance of Gal-3 expression requires a better understanding. OBJECTIVES: The aim of this paper was to evaluate Gal-3 expression in tongue carcinomas experimentally induced in mice challenged with carcinogen 4-nitroquinoline-1-oxide (4NQO). MATERIAL AND METHOD: Forty-two C57BL/6 male mice were challenged with 4NQO in drinking water for 16 weeks and killed at different periods after induction. In each period, their tongues were removed, routinely processed, stained with hematoxylin and eosin (H&E) and microscopically analyzed as to the presence of carcinoma. Immunohistochemical test for Gal-3 and a descriptive analysis of its expression in induced tumors were performed. RESULTS: By the end of the experiment, 15 tumors had been induced. In the non-neoplastic lingual epithelium, strong and weak immunoreactivity for Gal-3 was noted in parabasal and superficial layers, respectively. In the basal layer, Gal-3 expression varied from absent to weak. All the well-differentiated carcinomas showed weak immunoreactivity for Gal-3, except in keratinized areas. The only case of poorly differentiated squamous cell carcinoma indicated strong immunoreactivity for Gal-3. CONCLUSION: Our results show that malignant transformation is associated with reduced expression of Gal-3, whereas its increased expression in poorly differentiated carcinoma seems to be connected with tumor aggressiveness.

INTRODUÇÃO: Aproximadamente 80% das neoplasias malignas de pele não-melanomas são carcinomas basocelulares (CBC). Apesar das raras metástases, esses tumores são localmente agressivos. As metaloproteinases de matriz (MMPs), especialmente as MMP-2 e 9, são importantes no processo de invasão. Em contrapartida, os inibidores teciduais das MMPs (TIMPs) têm como principal função a inibição dessas enzimas. OBJETIVO: Investigar a associação de variáveis clinicopatológicas de pacientes portadores de CBC com a expressão de MMP-2, MMP-9, TIMP-1 e TIMP-2. MATERIAL E MÉTODOS: Foram selecionados 31 casos de CBC, sendo então obtidos, retrospectivamente, os dados referentes a idade, sexo e tamanho da lesão. Cortes histológicos das lesões foram submetidos a reação imuno-histoquímica pela técnica estreptavidina-biotina-peroxidase para detecção dos antígenos de interesse. Índices de imunomarcação foram construídos e comparados com os dados previamente obtidos. RESULTADOS: Observou-se correlação significativa entre idade e tamanho da lesão (R = 0,532; p = 0,008). Não foram observadas correlações significativas entre as outras variáveis e a expressão imuno-histoquímica dos antígenos de interesse. CONCLUSÃO: A expressão das metaloproteinases e de seus inibidores teciduais não parece ser influenciada pelos parâmetros investigados. Estudos adicionais são necessários para melhor compreensão de sua associação com o comportamento biológico do CBC.

INTRODUCTION: Approximately 80% of non-melanoma skin neoplasias are basal cell carcinomas (BCC). Although metastasis is rare, BBC carcinomas are locally aggressive tumors. Matrix metalloproteinases (MMPs), mainly MMP-2 and MMP-9, play an important role on the invasion process. On the other hand, tissue inhibitors of MMPs (TIMPs) have the main function of inhibiting these enzymes. OBJECTIVE: To investigate the association of clinical-pathological variables of BCC patients with the expression of MMP-2 and MMP-9, TIMP-1 and TIMP-2. Methods: Thirty-one BCC cases were selected. Gender, age of the patients and size of the lesions were obtained retrospectively. Histological cuts of the lesions were exposed to immunohistochemistry reaction by use of the streptavidine-biotin peroxidase technique in order to detect antigens. Immunomarking parameters were established and compared with previous data. RESULTS: A significant correlation between age and size of the lesion was observed (R = 0.532; p = 0.008). No significant correlations between other variables and immunohistochemical expression of antigens were observed. CONCLUSION: The expression of MMPs and TIMPs does not seem to be influenced by the parameters investigated in this work. Additional studies should be made to better understand its association with the biological behavior of basal cell carcinomas.

INTRODUÇÃO: A carcinogênese bucal é um processo multipassos no qual eventos genéticos promovem o rompimento de vias regulatórias normais que controlam funções celulares básicas. O carcinoma epidermóide de cavidade bucal (CECB) surge como conseqüência de múltiplos eventos moleculares induzidos pelos efeitos de vários carcinógenos influenciados por fatores ambientais contra um quadro de resistência ou suscetibilidade herdada geneticamente. OBJETIVO: Avaliar a importância clínica e morfológica da imunoexpressão das proteínas p53 e p16 na região do front invasivo de uma série de 35 casos rotineiramente processados de CECB. MATERIAL E MÉTODOS: Amostras de CECB primários tratados exclusivamente por cirurgia foram investigadas. O sistema TNM foi empregado para o estadiamento clínico dos pacientes. Para a gradação morfológica das lesões foi adotado o sistema de gradação do front invasivo. A técnica de imuno-histoquímica foi realizada nas lesões fixadas em formalina tamponada a 10% e emblocadas em parafina para identificação das proteínas p53 e p16. As contagens foram realizadas e submetidas a tratamentos estatísticos específicos. RESULTADOS: As taxas de imunolocalização para as proteínas p53 e p16 foram de 63% e 66%, respectivamente, nas 35 amostras de carcinoma estudadas. Não houve relação entre as expressões das proteínas p53 e p16 com os parâmetros clínico-morfológicos analisados. Não houve correlação entre a expressão imuno-histoquímica das proteínas p53/p16. CONCLUSÃO: A expressão das proteínas p53 e p16 não influenciou os parâmetros clínico-morfológicos analisados neste estudo e aparentemente não representa base molecular para o significado biológico da região do front invasivo tumoral. A ausência de forte correlação entre as expressões imuno-histoquímicas das proteínas p53 e p16 sugere que as mesmas podem participar de atividade biológicas do controle do ciclo celular por vias moleculares independentes.

BACKGROUND: Oral carcinogenesis is a multistep process in which genetic events lead to the disruption of the normal regulatory pathways that control basic cellular functions. Epidermoid carcinoma of oral cavity (ECOC) appears as a consequence of multiple molecular events induced by the effects of several carcinogens influenced by environmental factors against a background of genetic resistance or susceptibility. Consequent genetic damage affects many chromosomes and genes, and the accumulation of these changes seems to lead to ECOC. OBJECTIVES: The aim of the present study was to assess the clinical and morphological value of p53 and p16 immunolocalization at the invasive tumor front in a representative series of 35 routinely processed ECOC. MATERIAL AND METHODS: Samples of ECOC were investigated in this study. TNM system was employed for clinical staging and the invasive front grading system was employed for morphological grading of the lesions. Immunohistochemical technique in paraffin-embedded and formalin-fixed tissues was utilized to immunolocalization of p53 and p16 proteins. Counts were performed and submitted to specific statistical treatments. RESULTS: p53 and p16 immunolocalizations were detected in 63% and 66%, respectively, of 35 carcinomas studied. No correlation was found between p53 and p16 expressions and clinico-morphological parameters statistically analyzed. No correlation was found between the relationship p53/p16 expressions. CONCLUSION: p53 and p16 immunolocalization did not influence the clinico-morphological parameters analyzed in this study and apparently do not represent a molecular basis for the biologic significance of the invasive tumor front. Lack of a strong correlation between p53 and p16 immunolocalization suggests that both could participate in biological activities in the cell cycle control by independent molecular pathways.

INTRODUÇÃO: Mutações no gene TP53 têm sido identificadas em várias neoplasias, incluindo as de glândulas salivares (NGS). Entretanto não existe consenso sobre o significado biológico da expressão de p53 nessas lesões. OBJETIVOS: Avaliar a marcação imuno-histoquímica do antígeno p53 em NGS, investigando possíveis diferenças entre lesões benignas e malignas, entre diferentes tipos histológicos e entre tumores malignos que: 1) não desenvolveram metástases; 2) emitiram metástases; e 3) metástases de NGS. MATERIAL E MÉTODO: Foram avaliados 16 casos de adenomas pleomórficos (AP), 17 lesões malignas que não apresentaram metástase durante a proservação (sete carcinomas adenóides císticos [CAC] e dez mucoepidermóides [CM]), 13 tumores malignos que emitiram metástases (nove CAC e quatro CM) e, ainda, 12 metástases regionais ou distantes (cinco CAC e sete CM). Por marcação imuno-histoquímica (estreptavidina-biotina-peroxidase), índices médios de localização do antígeno p53 foram estabelecidos para cada tumor. Para análise, utilizaram-se testes de Mann-Whitney e Kruskal-Wallis, com nível de significância de 5%. RESULTADOS: Foram observadas diferenças estatisticamente significantes nos índices médios de imunomarcação de p53 entre lesões benignas e malignas (p = 0,03) e entre os diferentes tipos histológicos, notadamente entre o AP e o CM (p = 0,02). Todavia houve marcada sobreposição dos intervalos de índices de expressão entre os grupos testados. Nenhuma diferença de expressão foi observada entre as neoplasias malignas quanto ao seu comportamento metastático. CONCLUSÃO: Embora a expressão de p53 tenha sido detectada em todos os subtipos de NGS, a marcação imuno-histoquímica deste antígeno não permitiu discriminar os tumores malignos quanto ao seu comportamento biológico.

BACKGROUND: Mutations in the tumor suppressor gene TP53 have been found in many tumors, including salivary gland neoplasms (SGN). However, there is not consensus about the influence of p53 protein expression on the biological behavior of SGN. OBJECTIVES: To compare the expression of p53 between benign and malignant neoplasms, among histologic subtypes of those tumors, and among (1) tumors that did not metastasize; (2) primary lesions that emitted metastasis; and (3) metastasis of SGN, by immunohistochemistry. MATERIAL AND METHOD: It was evaluated 16 cases of pleomorphic adenoma (PA), 17 samples of primary malignant tumors that did not metastasize throughout preservation (seven adenoid cystic carcinoma [ACC] and ten mucoepidermoid carcinomas [MC]), 13 malignant neoplasms that emitted metastasis (nine ACC and four MC) and 12 regional or distant metastasis (five ACC and seven MC) by immunohistochemical detection of p53 antigen (streptavidin-biotin-peroxidase method). Statistical analyses were performed by Mann-Whitney and Kruskal-Wallis tests. p value below 0.05 was considered significant. RESULTS: A significant difference between benign and malignant lesions (p = 0.03) and among different histological types (p = 0.02) was observed, notably between PA and MC. Malignant lesions with distinct biological behavior did not differ according to this analysis.