Surgical treatment of malignant colon polyps / Tratamento cirúrgico do pólipo maligno do cólon

ABSTRACT Background: In the therapeutic decision about the malignant colon polyp, several factors predicting residual disease after the endoscopic resection guide the decision of surveillance or surgical intervention. This is a challenging decision, because even in the presence of high-risk predictors currently used, only 15-30% of the patients will have residual disease in the surgical specimen. Objective: To evaluate patients with a diagnosis of malignant colon polyp at the Hospital Center of São João, who were indicated for surgical treatment, studying the predictors of residual disease in the surgical specimen. Methods: A retrospective study was carried out, based on the patients with malignant colon polyp diagnosed and treated at the Hospital Center of São João in the city of Porto, Portugal, between 2009 and 2016. The endoscopic, anatomopathological, surgical and follow-up data were reviewed. Results: Of the total number of patients in the study (n = 96), 59 (61.5%) were indicated for surgery after a multidisciplinary discussion. Of this group, 21 patients (35.6%) had residual disease in the surgical specimen, with presence of lymph node invasion in 8 patients (13.6%). The presence of malignancy in the surgical resection specimen was statistically significantly associated with: size of the resected polyp (p = 0.023); sessile polyp (p = 0.007); piecemeal resection (p = 0.002). Conclusions: The persistence of malignancy in the surgical specimen was associated with larger sessile polyps and piecemeal removal. A significant number of patients did not show malignancy in the surgical resection specimen, with more markers being required to better stratify patients.

RESUMO Contexto: Na decisão terapêutica do pólipo maligno do cólon diversos fatores preditores de doença residual após a recessão endoscópica norteiam a decisão de vigilância ou intervenção cirúrgica. Esta é uma decisão desafiadora, uma vez que mesmo na presença dos preditores de alto risco usados atualmente, apenas 15% a 30% dos doentes terão doença residual na peça cirúrgica. Objetivo: Avaliar os doentes com diagnóstico de pólipo maligno do cólon no Centro Hospitalar de São João que foram orientados para tratamento cirúrgico, estudando os preditores de doença residual na peça cirúrgica. Métodos: Foi realizado um estudo retrospetivo, tendo por base os doentes com pólipo maligno do cólon diagnosticado e tratado no Centro Hospitalar de São João no Porto, Portugal, entre 2009 e 2016. Os dados endoscópicos, anatomopatológicos, cirúrgicos e o seguimento foram revistos. Resultados: Do total de doentes em estudo (n = 96); 59 (61,5%) tiveram indicação para cirurgia após discussão multidisciplinar. Deste grupo, 21 doentes (35,6%) apresentavam doença residual na peça cirúrgica, com presença de invasão ganglionar em 8 doentes (13,6%). A presença de malignidade na peça de ressecção cirúrgica associava-se de forma estatisticamente significativa a: tamanho do pólipo ressecado (p = 0,023); pólipo séssil (p = 0,007); ressecção em piecemeal (p = 0,002). Conclusões: A persistência de malignidade na peça cirúrgica associou-se a pólipos sésseis, de maiores dimensões e à remoção em piecemeal. Um número importante de doentes não apresentava malignidade na peça de ressecção cirúrgica, sendo necessários mais marcadores para melhor estratificar os doentes.

Pseudoinvasion in an Adenomatous Polyp of the Colon Mimicking Invasive Colon Cancer

Pseudoinvasion or pseudocarcinomatous invasion in an adenomatous polyp of the colon can be unfamiliar to an endoscopist. Pseudoinvasion in an adenomatous polyp represents prolapse of the adenomatous epithelium into its stalk. In most cases its morphology does not differ from of general adenomatous polyps, but in some cases it can morphologically mimic a malignant polyp with submucosal invasion due to mass- like lesioning of its stalk. This makes it difficult for endoscopists to differentiate pseudoinvasion in an adenoma from an invasive carcinoma by conventional endoscopy; instead, endoscopic ultrasonography can provide useful information for differentiating these conditions. We report on an 82-year-old man who presented with a large pedunculated polyp with a thick stalk in the sigmoid colon, which mimicked a submucosal invasive carcinoma. The patient was diagnosed with pseudoinvasion in an adenomatous polyp after segmental resection of the sigmoid colon.