Malignant Carcinoid Tumor Complicating Chronic Ulcerative Colitis

Abstract

A case of malignant carcinoid tumor (neuroendocrine carcinoma) of the cecum is described. The neoplasm arose in a patient who had chronic ulcerative colitis for 16 years. There is no previous documentation of this combination, which is surprising, in view of the known association of colonic adenocarcinomas and lymphomas with ulcerative colitis. The reasons for this discrepancy are discussed and it is postulated that ultrastructural examination of poorly differentiated colonic neoplasms may result in a more frequent identification of this association.

Solitary Microcarcinoid of the Rectal Stump in Ulcerative Colitis

“…In concurrence with this assumption, in three of them further glandular dysplasia or adenocarcinoma was found in the colorectal specimen [3, 4, 13]. The invasive potential of these lesions appears to be insignificantly lower (two cases, 33%) [3, 7]. According to Quinn and Platell [16], however, the initial steps of this pathway might be potentially reversible with regression of active inflammation.…”

“…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]. …”

“…In the 6 cases where a multifocal carcinoid was found, ulcerative colitis may be responsible for a ‘field-injury’ involving pluripotential stem cells on a vast area of colorectal lining [3, 4, 7, 13, 15, 16]. In concurrence with this assumption, in three of them further glandular dysplasia or adenocarcinoma was found in the colorectal specimen [3, 4, 13].…”