Resumo 24. Introdução: O adenocarcinoma ductal do pâncreas é uma das principais causas de morte por cancro. Apresenta uma baixa sobrevivência mesmo na pequena proporção de doentes submetidos a cirurgia. O objetivo deste estudo foi avaliar o valor da TC pré- operatória na previsão do envolvimento das margens cirúrgicas e identificar características imagiológicas preditoras de sobrevivência nos doentes com adenocarcinoma pancreático ressecável. 25. Métodos: Foram avaliados retrospetivamente 62 doentes com adenocarcinoma pancreático confirmado histologicamente e submetidos a ressecção cirúrgica entre 1 de janeiro de 2010 e 30 de junho de 2019. Os registos clínicos e as TC pré-operatórias foram revistos para recolha de dados clínicos e imagiológicos. Os dados foram avaliados com o teste do Qui- quadrado e regressão logística binária. A análise de sobrevivência realizou-se com recurso ao método de Kaplan-Meier, ao teste de Log-Rank e à regressão de Cox. 26. Resultados: Dos 62 doentes incluídos no estudo, identificaram-se 35 com margens negativas e 27 com margens positivas. Na análise multivariada, o contacto vascular revelou- se preditor de margens cirúrgicas positivas. A sobrevivência média foi de 26,3 meses, sendo significativamente diferente entre os grupos com margens positivas e negativas. Na análise de sobrevivência, a densidade tumoral na TC (HR=0,985, p-value=0,035) e sinais imagiológicos sugestivos de envolvimento perineural extra-pancreático (HR=2,324, p-value=0,048) foram identificados como preditores de sobrevivência. 27. Conclusão: A TC pré-operatória é uma ferramenta útil na previsão das margens cirúrgicas positivas e sobrevivência, podendo ajudar na identificação de doentes com tumores ressecáveis com pior prognóstico que possam beneficiar de outras estratégias terapêuticas.

Abstract 32. Introduction: Pancreatic ductal adenocarcinoma is one of the most common causes of cancer- related death. The overall survival is short even in the small proportion of patients who are eligible for surgical resection. The aims of our study were to assess the value of preoperative CT scan in the prediction of the surgical margin status and to identify imaging features that predict the survival of patients with resectable pancreatic adenocarcinoma. 33. Methods: Our study included 62 patients with histologically confirmed pancreatic adenocarcinoma, who underwent surgery between January 1st 2010 and June 30th 2019. Medical records and preoperative CT images were reviewed in order to collect clinical and imaging data. Data was analyzed with the Chiquare test and binary logistic regression. Kaplan-Meier estimates, Log-Rank test, and multivariate Cox proportional hazards regression were used for the survival analysis. Results: From the 62 patients who underwent surgery, negative surgical margins were achieved in 35 of them and 27 patients had positive surgical margins. In the multivariate analysis, vascular contact was a predictor of positive surgical margins. The mean survival was 26,3 months, being significantly different between the two groups of surgical margins. In survival analysis, tumor density on CT (HR=0,985, p-value=0,035) and imaging signs of extra- pancreatic perineural involvement (HR=2,324, p-value=0,048) were identified as predictors of survival. 34. Conclusion: Preoperative CT is a useful tool to predict positive surgical margins and survival. It helps to identify patients with resectable tumors but worse prognosis who can benefit from different therapeutic strategies.

ABSTRACT Appendiceal tumors comprise a variety of histologic types, including appendiceal mucinous neoplasms, which can be grouped as premalignant lesions, tumors of uncertain malignant potential, and malignant lesions. The appendiceal mucinous neoplasms are characterized by mucinous epithelial proliferation with extracellular mucin and pushing tumor margins, commonly an incidental finding during operative exploration. We report the case of a low-grade appendiceal mucinous neoplasm presenting as a subepithelial lesion in Crohn´s Disease patient. The diagnosis was not straightforward, and only surgical resection allowed an accurate diagnosis. Although Inflammatory Bowel Disease is a risk factor for the development of colorectal neoplasms, the absolute risk for appendiceal tumors is uncertain. The frequency of progression to malignancy remains to be determined.

ABSTRACT Actinomycosis is an uncommon, endogenous, and chronic infection with varied and nonspecific clinical features such as abdominal, pelvic or cervical masses, ulcerative lesions, abscesses, draining fistula, fibrosis, and constitutional symptoms. The disease ensues when the bacteria disrupt the mucosal barrier, invade, and spread throughout interfascial planes. Currently, the diagnosis of actinomycosis is challenging because of its very low frequency and depending on the clinical presentation it may masquerade malignancies. Therapy consists initially in intravenous penicillin, followed by an oral regimen that may be extended until a year of treatment. A timely diagnosis is crucial to avoid extensive therapeutic attempt as surgery. However, a biopsy or drainage of abscesses and fistula’s tract may be required not only as a diagnostic procedure as part of the therapy. We report the case of a 72-year-old woman with an abdominal mass initially misdiagnosed as a liposarcoma. A second biopsy of a skin lesion of the abdominal wall made the diagnosis of actinomycosis, avoiding a major surgical procedure. The patient was treated with a long-term course of antibiotics with favorable outcome. Liposarcoma was ruled out after the patient’s full recovery with antibiotics and the misdiagnosis was credit to the overconfidence on the immunohistochemical positivity to MDM2.