Abstract Psoriatic arthritis (PA) usually presents as oligoarthritis or monoarthritis and can be a diagnostic challenge in the absence of psoriasis background. We report the case of a 57-year-old patient who presented to the Family Physician (FF) after one year of inflammatory signs and onycholysis of the 3rd finger of the right hand. Initial exams showed signs of inflammation from the periungueal tissues to the distal interphalangeal joint, and negative analytical inflammatory parameters. The condition was interpreted in an infectious context and, later, as osteoarthritis, without improvement with the instituted treatments. The disease and the diagnosis delay had significant psychological and professional impact on the patient. This case reports a rare presentation of PA, that could increase the diagnostic suspicion of this entity in Primary Health Care and highlights the role of the FF in the holistic follow-up and management of patient expectations, besides articulation with other specialties.

Resumo A artrite psoriática (AP) apresenta-se, habitualmente, como uma oligoartrite ou monoartrite, e pode constituir um desafio diagnóstico na ausência de história de psoríase. Relata-se o caso de um paciente de 57 anos que recorreu ao Médico de Família (MF) após um ano de evolução de sinais inflamatórios e onicólise do 3º dedo da mão direita. Os exames iniciais mostravam sinais inflamatórios dos tecidos peri-ungueais até à articulação interfalângica distal, e parâmetros inflamatórios analíticos negativos. O quadro foi interpretado em contexto infecioso e, posteriormente, como osteoartrose, não tendo existido melhoria com os tratamentos instituídos. A doença e o atraso no diagnóstico tiveram significativo impacto psicológico e profissional no paciente. Este caso relata uma apresentação rara de AP, podendo aumentar a suspeição diagnóstica desta entidade nos Cuidados de Saúde Primários, e evidencia o papel do MF no acompanhamento holístico e gestão das expectativas do paciente, além da articulação com as outras especialidades.

Resumen La evaluación de la expresión del ligando 1 de muerte programada (PD-L1) es un criterio de elegibilidad para la inmunoterapia anti-PD-L1 en el carcinoma oral de células escamosas (COCE). También deben evaluarse otros componentes del microambiente tisular. Aquí se informaron cuatro casos de carcinoma de células escamosas orales. Se realizaron análisis histopatológicos del grado tumoral y TIL (infiltrado inflamatorio asociado a tumor) e inmunohistoquímica para CD4, CD8 y PD-L1. Los casos se clasificaron según el microambiente tisular en resistencia inmunitaria adaptativa, ignorancia inmunológica, tolerancia o inducción intrínseca. Este análisis destaca la importancia de comprender el microambiente inmunológico que puede presentar el COCE para la identificación de dianas terapéuticas más eficaces contra la enfermedad.

Abstract The evaluation of the expression of programmed cell death protein (PD-L1) is an eligibility criterion for anti-PD-L1 immunotherapy in oral squamous cell carcinoma (OSCC). Other components of tissue microenvironment should also be evaluated. Here, four cases of oral squamous cells carcinoma were reported. Histopathological analysis of tumor grade and TILs and immunohistochemistry for CD4, CD8, and PD-L1 was done. The cases were classified according to the tissue microenvironment in adaptive immune resistance, immunological ignorance, tolerance, or intrinsic induction. This analysis highlights the importance of understanding the immunological microenvironment that the OSCC can present for the identification of more effective therapeutic targets against the disease.

Resumo A pandemia COVID-19 obrigou a uma rápida adaptação dos serviços de saúde para que se pudesse manter a resposta e qualidade dos cuidados. De forma a garantir a acessibilidade dos utentes aos cuidados de saúde primários e minimizar as consequências do distanciamento social, oferecendo alternativas à consulta presencial, a nossa Unidade de Saúde Familiar (USF) criou a linha de apoio ao utente. Os profissionais da USF adquiriram de forma autónoma seis telemóveis e criaram seis linhas diferentes: duas linhas para apoio médico geral, duas linhas para assuntos relacionados com a COVID-19, uma linha de apoio de enfermagem e uma linha de apoio do secretariado clínico. Foi criada uma base de dados para registo de contactos médicos e de enfermagem. Esta base de dados permitiu ainda a referenciação direta a apoio de psicologia. Avaliou-se um período de seis meses (entre 16 de março e 16 de setembro de 2020). Foram registadas 7.535 chamadas: 5.281 nas linhas de apoio médico geral e 230 nas linhas médicas relacionadas com a COVID-19. Foram feitas 51 referenciações para apoio psicológico. As restrições que obrigaram a medidas extraordinárias serão levantadas e esta experiência pode fornecer bases para o futuro, nomeadamente como diversificar a acessibilidade de uma unidade de saúde familiar, salientando a necessidade de investimento nessa área. No contexto atual, a telemedicina tem-se revelado uma alternativa adequada para o atendimento e orientação dos utentes.

Abstract The COVID-19 pandemic forced a quick adaptation of the health services so that the response and quality of care could be maintained. In order to guarantee the accessibility of users to primary health care and minimize the consequences of social distancing, offering alternatives to face-to-face consultation, our family health unit created a support line for the patients. The health professionals of this primary health care facility purchased six mobile phones and created six different helplines: two lines for general medical support, two lines for matters related to COVID-19, a nursing support line, and a support line for clinical secretaries. A database was created to record all telephone contacts. This database also allowed direct referral to psychological support. The record of the clinical secretaries’ line was discontinued. A six-month period was evaluated (between March 16 and September 16, 2020). 7,535 calls were registered: 5,281 to the general medical support lines, 230 to the medical lines related to COVID-19, and 2,024 to the nursing support lines. Fifty-one referrals were made for psychological support. The restrictions that forced extraordinary measures will be lifted one day and this experience may provide some knowledge for the future, regarding how to diversify the accessibility of a primary health care facility and highlight the need for investment in this area. In the current pandemic situation, telemedicine has proven to be an adequate alternative for the care and guidance of users.

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.

Resumo Introdução: O pé pendente define-se pela incapacidade em elevar o pé por diminuição da força dos músculos dorsiflexores. Para elaborar um plano de tratamento é necessário determinar a sua etiologia. Cabe, assim, ao médico de família reconhecer as situações em que a gestão desta entidade poderá ser feita exclusivamente em cuidados de saúde primários, diferenciando-as das que poderão exigir avaliação e orientação em meio hospitalar. Descrição do Caso: Homem de 71 anos com hipertensão arterial e dislipidemia, medicado com indapamida. Em consulta com o médico de família referia que, há dois dias, havia permanecido sentado por duas horas com a perna direita cruzada sobre o membro inferior contralateral. Ao levantar-se notou dormência do pé direito, o qual não conseguia elevar. À observação apresentava marcha em steppage, com pé direito pendente e diminuição da sensibilidade do dorso do mesmo. Foi pedida eletromiografia, que documentou acentuada lesão axonal do nervo peroneal comum direito abaixo do colo do perónio, compatível com compressão prolongada. Foi submetido a sessões de fisioterapia, demonstrando resolução completa do quadro após três meses. Comentário: A neuropatia do nervo peroneal comum é a causa principal de pé pendente e a terceira neuropatia focal mais frequente, depois do nervo mediano e nervo cubital. A etiologia mais frequente é a compressiva. O local mais afetado é onde o nervo contorna o colo do perónio, manifestando-se por marcha em steppage, consequente à diminuição da força dos músculos dorsiflexores do pé. Embora o diagnóstico seja habitualmente clínico, a maioria dos pacientes requer eletromiografia. O tratamento inicial costuma ser conservador, sendo comum ocorrer resolução das queixas em três meses. Esta é uma condição que poderá ser pouco frequente na prática clínica em medicina geral e familiar, mas cuja abordagem poderá, muitas vezes, ser feita em cuidados de saúde primários. É importante saber tranquilizar os pacientes quanto à semiologia, abordagem terapêutica e prognóstico.

Abstract Introduction: Foot drop is defined by the inability to elevate the foot due to diminished strength of the dorsiflexor muscles. To elaborate a treatment plan, it is necessary to determine its etiology. Thus, the family doctor must recognize the situations in which the management of foot drop can be done exclusively in primary health care, differentiating from those that may require observation and assessment in-hospital care. Case description: 71-year-old man with arterial hypertension and dyslipidemia, medicated with indapamide. An appointment with the family doctor referred that, two days ago, had remained seated for two hours with the right leg crossed over the contralateral lower limb. By getting up, the patient noticed right foot numbness and inability to elevate the same foot. At the physical examination, he presented a steppage gait, with right foot drop and decreased sensitivity of the back of the foot. It was requested electromyography, which documented severe axonal damage of the right common peroneal nerve below the fibular neck, compatible with prolonged compression. The patient was submitted to physiotherapy sessions, demonstrating complete clinical resolution of foot drop after three months. Comment: The neuropathy of the common peroneal nerve is the main cause of foot drop and the third most frequent focal neuropathy, after the median nerve and cubital nerve. Compression remains the most frequent etiology. The most affected site is at the level of the fibular neck, manifested by steppage gait, consequent to decreased strength of the dorsiflexor muscles of the foot. Even though the diagnosis is usually clinical, most of the patients require electromyography. The initial treatment tends to be conservative, with a frequent resolution of the complaints in three months. This is a condition that may be uncommon in family medicine’s clinical practice, but its approach could be, many times, managed in primary health care. It is important to know how to reassure the patients about the semiology, therapeutic approach, and prognosis.

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.

Objetiuo:Analisar os resultados entre 1984 e 2004 em nossa instituição do tratamento cirúrgico de 69 pés equinovaros em 43 pacientes portadores de mielodisplasia segundo os critérios clínico e radiográfico.Métodos:Estudo retrospectivo com análise de prontuário, radiografias e consulta com pacientes portadores de mielomeningocele que foram submetidos a correção cirúrgica de pés equinovaros. A técnica cirúrgica foi a liberação posteromediolateral (LPML) radical associada ou não a talectomia.Resultados:A média de idade na época da cirurgia foi de quatro anos e dois meses e o seguimento médio pós-operatório, de sete anos e dois meses. Foram encontrados resultados satisfatórios em 73,9% dos pés e insatisfatórios em 26,1% (p < 0,0001).Conclusão:A deformidade residual no pós-operatório imediato está relacionada com resultados insatisfatórios e a abertura do ângulo de Kite (talocalcaneano) nos pés submetidos somente a LPML, além do posicionamento adequado do calcâneo, nos casos em que foi feita a talectomia, é o parâmetro radiográfico relacionado aos resultados satisfatórios.

Objective:To analyze the results from surgical treatment of 69 cases of clubfoot in 43 patients with myelodysplasia according to clinical and radiographic criteria, at our institution between 1984 and 2004.Methods:This was a retrospective study involving analysis of medical files, radiographs and consultations relating to patients who underwent surgical correction of clubfoot. The surgical technique consisted of radical posteromedial and lateral release with or without associated talectomy.Results:The patients' mean age at the time of the surgery was four years and two months, and the mean length of postoperative follow-up was seven years and two months. Satisfactory results were achieved in 73.9% of the feet and unsatisfactory results in 26.1% (p < 0.0001).Conclusion:Residual deformity in the immediate postoperative period was associated with unsatisfactory results. Opening of the Kite (talocalcaneal) angle in feet that only underwent posteromedial and lateral release, along with appropriate positioning of the calcaneus in cases that underwent talectomy, was the radiographic parameter that correlated with satisfactory results.

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.

Os aneurismas do segmento extracraniano da carótida interna são lesões raras, de etiologia diversa e relativamente aos quais o conhecimento actual tem resultado da publicação de pequenas séries e casos clínicos isolados. Apresenta-se o caso de uma doente com um aneurisma degenerativo da carótida interna que foi submetida a tratamento cirúrgico e discute-se o quadro clínico e a estratégia terapêutica adoptada

Atherosclerotic extracranial internal carotid aneurysms are a rare entity and have diverse etiologies. Comprehensive information about these lesions is difficult to obtain and has resulted from the publication of small series and isolated clinical reports. The authors report the case of an atherosclerotic carotid aneurysm submitted to surgical treatment and discuss the clinical presentation and surgical strategy.

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.