Polypes coliques malins : critères histologiques en vue de ľévaluation du traitement endoscopique

Abstract

Endoscopic resection of neoplastic colonie polyps is a generally accepted treatment. It is also accepted that colonoscopy is the best follow-up method for patients with colonic adenomas.Adenomas with malignant epithelial areas were and are also treated by endoscopy. The therapeutical attitude in patients with malignant polyps in less clear and has been based on empirical criteria. During the last years various reports have been published discussing the management of malignant colonic polyps. They allow us to improve the planning of the further therapeutical attitude. We studied 58 patients treated for 65 malignant polyps and compared our findings with the data of the literature. The resection specimen with draining lymph nodes, coming from 17 patients who underwent an adjuvant colectomy were reexamined and fourty eight patients have been followed for a mean period of 6 years by clinical observation, endoscopy and sonography.The histological criteria studied are : 1. level of invasion of the carcinomatous component ; 2. the extent of carcinomatous involvement ; 3. the presence of vascular invasion ; 4. the degree of tumor differentiation ; 5. assessment of section margins ; 6. polyp type, size and shape. From the results of our study and from the data of the literature we can conclude that an accurate judgment of the resection margin, the degree of differentiation of the carcinomatous component and vascular invasion are important criteria for the determination of further therapeutical attitude. Accurate orientation of the poiyp is of essential importance for adequate assessment of the resection. Fragmentation of the lesion during the resection must be avoided.Malignant polyps can successfuly be treated by polypectomy on the condition that the resection margin is negative and that the carcinoma is not undifferentiated. The importance of vascular invasion cannot yet adequately be evaluated.