Malignant potential of polypoid lesions of the colon and rectum

Department of Pathology, Henry Ford Hospital, Detroit, Mich.
Cancer (Impact Factor: 4.89). 07/1971; 28(1):146 - 152. DOI: 10.1002/1097-0142(197107)28:1<146::AID-CNCR2820280130>3.0.CO;2-G


More than half of some 2000 polypoid lesions of the colon and rectum studied in the Department of Pathology of Henry Ford Hospital, over a recent 5-year period, were diagnosed as adenomatous polyps. Approximately one quarter were considered non-neoplastic—hyperplastic, mucosal, and inflammatory polyps. Little evidence can be found to support a contention that any of these lesions predispose to the development of cancer; origin of carcinoma in such polyps is believed to be a rare event. The papillary or villous adenoma, on the other hand, is a potentially serious lesion. Although the incidence of progression to frank cancer does not appear great, many papillary adenomas, particularly the larger ones, contain foci of invasive cancer. Additionally, even when they do not, there is a risk of repeated local recurrence unless bowel resection is carried out. It appears that most carcinomas are carcinomas from their inception.

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    ABSTRACT: Carcinoma in situ was found in 16.0% of patients with histologically verified cases of solitary and multiple adenomatous polyps of the colon and rectum. In patients with adenomatous polyps only, the incidence was 6.1%. The incidence rose to 47.0% in the group of patients having adenomatous polyps associated with carcinoma in the same segment of the colon. This figure suggests that the diagnosis of carcinoma in situ in a polyp should be followed by careful search for frank adenocarcinoma in the proximity. Organ tissue cultures on the fibrin foam matrix demonstrated a morphological transition from cytologically benign adenomatous polyps into focal carcinoma in situ in more than two thirds of cultured cases. Moreover, a few of these polyps developed invasive features similar to those observed in cultures of colonic adenocarcinoma. The behavior of adenomatous polyps in tissue culture suggests a malignant potential of those lesions and their possible ability to become not only histologic, but also biologic cancers.
    Preview · Article · Nov 1972 · Cancer
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    ABSTRACT: The malignant potential of adenomas of the colon and rectum varies with size, histological type and grade of epithelial atypia. The adenomatous polyp is usually small and has a low malignant potential, whereas tumors with a villous structure are usually larger and have a much higher cancer rate. Severe atypia is more common in villous adenomas than in adenomatous polyps. Evidence is presented which suggests that most cancers of the colon and rectum have evolved through the polyp-cancer sequence although the majority of adenomas do not becoma cancerous during a normal adult life span. The slow evolution of the polyp-cancer sequence is stressed. The implications of the polyp-cancer sequence for the design of cancer prevention programmes and the study of the aetiology of large bowel cancer are discussed.
    Preview · Article · Jan 1976 · Cancer
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    ABSTRACT: Summary The management of colorectal polyps should be highly individualized. In arriving at a therapeutic decision concerning the treatment of invasive carcinomas arising in colonic polyps, one should have a basic knowledge of the polyps' malignant potential and propensity to metastasize. It is optimal to confirm the presence of invasive malignancy by excisional biopsy examination and weigh the risk of the patient's having involved lymph nodes against the risk of undertaking radical operative treatment. The results reported here give an accurate indication of the risks of metastatic nodal involvement in different types of polyps containing invasive carcinoma.
    No preview · Article · Apr 1979 · Diseases of the Colon & Rectum
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