Small bowel adenocarcinoma with high levels of microsatellite instability in Crohn's disease

Small bowel adenocarcinoma in Crohn disease: CT-enterography features with pathological correlation

“…These reports rather suggest a dysplasia-carcinoma sequence [39]. An association between microsatellite instability and neoplastic development similar to that of hereditary nonpolyposis colorectal carcinoma (the so-called Lynch syndrome) has also been reported [31]. Microsatellite instability was present in the two cases of our series in which it was searched for.…”

“…Results of immunohistochemical staining of the tumors for DNA mismatch repair gene products were available in two cases (patients 3 and 5) and indicated high levels of microsatellite instability (MSI), which was further confirmed by MSI testing [31].…”

Gastrointestinal cancers in inflammatory bowel disease: An update with emphasis on imaging findings

“…De novo small bowel adenocarcinoma arises through an adenoma-carcinoma sequence, with mutations in key growth-regulating genes such as k-Ras, APC, beta-catenin, p-53 mutation and mismatch repair protein (Aparicio et al, 2014;Arber et al, 1999;Delaunoit et al, 2005;Sellner, 1990;Chan et al, 1990). An association between microsatellite instability and neoplastic development similar to that of hereditary non polyposis colorectal carcinoma has been reported (Chan et al, 2006). However, more studies are needed to improve the understanding of the pathogenesis of IBD-related small bowel adenocarcinomas.…”

Small bowel adenocarcinoma in Crohnʼs disease

“…This is primarily due to poor accessibility of the small bowel for study. 10,21 Several theories have been postulated to explain the rare occurrence of small bowel adenocarcinoma 2,22-25 :…”

“…2 In CD-associated small bowel adenocarcinoma, an association between microsatellite instability and neoplastic development similar to Hereditary Nonpolyposis Colorectal Carcinoma has been described. 2,21 A dysplasia-carcinoma sequence attributed to chronic inflammation has been proposed as the underlying cause for malignant progression in CD, as evidenced by the localization of adenocarcinomas in inflammatory strictures (Table 1). 6,14,26 The most common histologic type of malignant tumor in the small intestine as per the registry data from the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute was adenocarcinoma, followed by carcinoid, lymphoma, and sarcoma, respectively.…”