Resolving Microcarcinoids in Ulcerative Colitis: Report of a Case

Abstract

Ulcerative colitis is known to predispose to the development of neoplasia, especially adenocarcinoma. Microcarcinoids represent small nests of gut endocrine cells located in the mucosa and submucosa of the bowel. Such lesions have been identified in association with chronic inflammation and the concern is that they may represent a precursor lesion for invasive carcinoid tumors. Yet carcinoid tumors are rarely reported in patients with ulcerative colitis. This case report documents a 56-year-old male with ulcerative colitis who was found on random biopsies to have microcarcinoids in his rectal submucosa. Following treatment of his colitis, there was complete resolution of both the inflammation and the microcarcinoids. However, on subsequent follow-up at six months, the patient's colitis has returned and so have the microcarcinoids. We explore the issue of whether these lesions represent true neoplasias that should be resected, or whether they represent cellular hyperplasia in response to the inflammatory stimulus.

Solitary Microcarcinoid of the Rectal Stump in Ulcerative Colitis

“…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]. …”

“…The coexistence of ulcerative colitis and carcinoid with neuroendocrine cell hyperplasia in several cases has, to several authors [4, 8, 13, 16,] suggested a stepwise sequence similar to that observed for microcarcinoid of the stomach in patients with pernicious anemia [21]. Though the parallel with gastric microcarcinoid might be inappropriate (on the contrary of ulcerative colitis, active mucosal inflammation is scarce in atrophic gastritis), the concept of chronic injury activating the sequence – normal endocrine cell, hyperplasia, microcarcinoid – remains to be disputed.…”

“…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].…”

“…Quinn and Platell [16] proposed the theory after observing a patient with multiple submucosal nests of carcinoid tumor arising on a background of ulcerative proctitis; after 6 weeks’ therapy, a substantial regression of inflammation was seen on flexible sigmoidoscopy and no more evidence of carcinoid cell was found on biopsies. In patients with ulcerative colitis, according to the authors, the proliferative changes of gut endocrine cells, including microcarcinoids, may not represent true neoplastic transformation and may undergo regression with the resolution of inflammation.…”

“…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.…”