Stem cell carcinoma of the colon and rectum

Abstract

Two cases of highly malignant tumors, one originating in the sigmoid colon and the other in the rectum, are presented. Both tumors showed light microscopic, electron microscopic, and immunohistochemical evidence of multidirectional differentiation. The tumors were composed mainly of undifferentiated cells, but focally merging into areas with adenocarcinomatous and squamous differentiation. Ultrastructurally and histochemically, a predominant endocrine differentiation was present in the undifferentiated areas of the tumors. These two cases lend further support to the recent concept of a pluripotential stem cell in the mucosa of the gastrointestinal tract capable of differentiation in several directions.

Small cell undifferentiated (‘neuroendocrine’) carcinoma of the colon

“…( 1 983), both the primary tumour and the hepatic metastases contained islands of 'benign appearing' squamous cells, whilst in two cases reported by Palvio et al (1985), foci of adenocarcinomatous and squamous differentiation were present. Further, single case reports of mixtures of undifferentiated, carcinoid and neuroendocrine elements with adenocarcinoma (Petrelli, Tetangco & Reid 1981, Damjanov, Amenta & Bosman 1983, Schwartz & Orenstein 1985 and the well-known combinations of adenoma, adenocarcinoma and carcinoid tumour (Klappenbach et al 1985) are against a simple derivation of such tumours, whether benign or malignant, from enteric neuroendocrine cells.…”

“…Dense core granules described as being of neuro-secretory type were present in variable amounts but were never numerous: the appearances seen in our case 3 resemble those previously illustrated. Further evidence of the 'neuroendocrine' nature of these tumours has included the presence of vanillyl-mandelic acid, 5-hydroxyindole acetic acid and catecholamines (Gould & Chejfec 1978) and a variable degree of argyrophilia by the Grimelius method (Mills et al 1983, Palvio et al 1985, Molas et al 1987.…”

“…The authors of all reports to date have drawn a parallel with 'oat cell' carcinoma of the lung and of other organs but expressed differing views on histogenesis. Nine of 24 cases reported so far arose in close association with a villous or tubulo-villous adenoma (Mills et al 1983, Palvio et al 1985, Molas et al 1987, Wicket al 1987, Chen 1989.…”

Primary Submucosal Squamous Cell Carcinoma of the Rectum Diagnosed by Endoscopic Ultrasound: Case Report and Literature Review

“…The etiology of colorectal SCC is still unclear. Some authors proposed the role of stem cell differentiation [10]. Others pointed on possible squamous metaplasia [8] or squamous differentiation in areas of preexisting adenomas [9].…”

“…The etiology of colorectal SCC is still unclear. Different proposals regarding its origin and its relation to other entities have been reported in the literature [2, 89101112131415]. We report a case of primary submucosal colorectal SCC which was diagnosed based on endoscopic ultrasound (EUS) fine needle biopsy and treated successfully with chemoradiation without preceded surgery upon the patient's request.…”