Intestinal low-grade tubuloglandular adenocarcinoma in inflammatory bowel disease
ABSTRACT Chronic idiopathic inflammatory bowel disease (IBD) with extensive colonic involvement predisposes to the development of colorectal adenocarcinoma. Among the types of cancer occurring in this setting is an unusually well-differentiated low-grade tubuloglandular adenocarcinoma (LGTGA) that has not been studied systematically thus far. A review of 149 IBD-associated cancer resections performed at our institution yielded 17 patients (11%) with 21 tumors classified as LGTGA based on the following histologic characteristics: very well-differentiated small to medium diameter glands with round or tubular profiles, low-grade cytologic characteristics and absence or paucity of desmoplastic reaction. Twelve patients had ulcerative colitis, 4 Crohn disease, and 1 indeterminate colitis. Their median age was 41.5 years (range, 28 to 58 y). Five patients had separate synchronous cancers of conventional types. LGTGAs ranged from 0.4 to 10 cm in size and varied in gross appearance. They included 5 flat lesions that were not identified visually but were detected either by palpation of the unfixed surgical specimen (1 case) or histologically in random sections (4 cases). The invasive glands usually bore a close histologic resemblance to overlying low-grade or indefinite dysplastic crypts. Twelve carcinomas (57%) with well-defined superficial regions of LGTGA progressed histologically to conventional adenocarcinoma in deeper regions. These tumors were significantly more advanced than 9 carcinomas that maintained low-grade histology throughout. Follow-up of 13 patients (76%) for a mean 4.0 years (range, 0.75 to 9.0 y) disclosed 10 (77%) with favorable outcomes and 3 (23%) with adverse outcomes. Two adverse outcomes were attributable to synchronous advanced-stage conventional cancers and the third to progression from LGTGA to poorly differentiated adenocarcinoma. The mucosa overlying and surrounding LGTGA showed low-grade dysplasia (LGD) in 18 cases (86%), indefinite dysplasia with focal LGD in 1 case (5%), and LGD with focal high-grade dysplasia (HGD) in 2 cases (10%). Immunohistochemical studies disclosed expression of MUC2 in 72%, MUC6 in 0%, CK7 in 69%, and CK20 in 100%. Coexpression of CK7 and CK20 was conserved in regions of conventional adenocarcinoma derived from LGTGA. Silencing of immunohistochemical expression of hMLH1 occurred in 6 of 11 tumors tested (55%), implicating defective DNA replication error repair in their pathogenesis. We conclude that LGTGA is a distinct clinicopathologic entity characterized by direct derivation from LGD mucosa of IBD, very well-differentiated morphology, frequent coexpression of CK7 and CK20, and frequent silencing of hMLH1. Histologic progression from LGTGA to conventional types of adenocarcinoma parallels clinical progression to more aggressive neoplasia. The potential of LGD to give rise directly to LGTGA, and by way of LGTGA to more aggressive cancers, reinforces recommendations in favor of aggressive management of IBD patients diagnosed with LGD.
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ABSTRACT: Gastrointestinal histopathology represents approximately half of the current work-flow in our laboratory, and six to ten of the reports signed out daily concern patients studied for Crohn’s disease (CD). This chapter summarizes the role of the pathologist in the management of patients with CD, starting from a glossary of the terms used in the information exchange between the pathologist radiologist gastroenterologist, and surgeon. This multidisciplinary team approach is crucial for the correct management of CD patients. The gastrointestinal tract has limited patterns of tissue response to triggers of inflammation and the diagnosis therefore relies upon the various combinations of these patterns with the clinical picture. The study of endoscopic specimens is based not only on a histopathological scheme but also on the presentation of the patient, which is of equal importance. Due to the limits in the information that can be extracted by studying the morphology of inflammation, molecular biology is expected to play an increasingly important role in providing the clinician with insight into the disease process in a single CD patient and thus in allowing the appropriate treatment strategy to be tailored accordingly.01/1970: pages 31-41;
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ABSTRACT: Patients with inflammatory bowel disease, either Crohn disease or ulcerative colitis, are at an increased risk for developing colorectal carcinoma. Surveillance colonoscopy, although never formally evaluated in a prospective controlled trial, is performed in an effort to reduce this risk. Novel methods of detecting dysplasia are constantly being evaluated, including chromoendoscopy and biomarkers of carcinoma, in an attempt to stratify patients who are at a higher risk of developing high-grade dysplasia or carcinoma. Because of the potential impact on quality of life and life expectancy, an optimal strategy for reducing the risk of developing colorectal cancer in patients with inflammatory bowel disease needs to be defined.Current Opinion in Gastroenterology 02/2004; 20(1):43-8. DOI:10.1097/00001574-200401000-00009 · 3.66 Impact Factor