Carcinoid tumor complicating ulcerative colitis

Solitary Microcarcinoid of the Rectal Stump in Ulcerative Colitis

“…In 9 cases including the present one, no multifocality was described [4,5,6,8,9,10, 12, 14]. Hypothetically, in these subjects, the chronic inflammation related to ulcerative colitis induced a ‘point-injury’ on the colorectal mucosa activating the sequence for carcinoid development.…”

“…To date, 20 cases of colorectal carcinoid arising on ulcerative colitis have been reported [3,4,5,6,7,8,9,10,11,12,13,14,15,16,17](table 1). Further carcinoids of the ileum or the appendix have been found in six patients with ulcerative colitis [19, 20].…”

“…Despite improvements in diagnostic technology, the frequency of case reports has not been increasing throughout the last 25 years: 12 cases from 1979 to 1991 [3,4,5,6,7,8,9,10,11], 6 cases from 1992 to present [12,13,14,15,16]. Hence, though the available literature might underestimate the actual incidence, the association of carcinoid with ulcerative colitis remains an exceptional event; accordingly, we could speculate that the coexistence of the two diseases represents independent events with no cause and effect relationship.…”

“…Though this may be an adaptive epiphenomenon, it cannot be excluded that this finding indeed reflects the increased proliferative pressure exerted by various inflammation-related factors on residual colonic stem cells. The development of carcinoid as a ‘reactive’ process to the chronic mucosal damage induced by ulcerative colitis is also indirectly supported by the following features: long previous history of ulcerative colitis (more than 5 years in 72% of subjects) [3,4,5,6,7,8, 10, 11, 14, 15], multifocal distribution in ulcerative colitis-affected mucosa (33% of the cases) [3, 4, 7, 13, 15, 16], concomitant development of colorectal dysplasia or adenocarcinoma (28% of the cases) [3, 4, 6, 13]. …”

“…Hypothetically, in these subjects, the chronic inflammation related to ulcerative colitis induced a ‘point-injury’ on the colorectal mucosa activating the sequence for carcinoid development. In seven of them (78%) an invasive carcinoid was found [5, 6,9,10,11, 14], indicating that this pathway harbors malignant potential.…”