Squamous Cell Carcinoma in Situ Arising in Inflammatory Cloacogenic Polyps: Report of Two Cases With PCR Analysis for HPV Dna

Abstract

Inflammatory cloacogenic polyp (ICP) is regarded as part of the spectrum of pathological changes encountered in mucosal prolapse syndrome (MPS)/solitary rectal ulcer. We present the clinicopathological features of two females with squamous cell carcinoma in situ arising in their ICPs. Human papillomavirus (HPV) type 16 was demonstrated in the areas of squamous carcinoma in situ in both polyps by polymerase chain reaction. These cases highlight the need for close scrutiny of the squamous components of these lesions.

Primary adenosquamous carcinoma of the colon: Report of five cases

“…It is suggested the carcinoma is derived from pluripotent stem cells towards multidirectional differentiation at the basal part of crypt, 13 squamous metaplasia of glandular epithelium under chronic irritation, or squamous differentiation of adenomas and adenocarcinomas. 4,14,15 According to Balfour,16 true SCCs of the colon and rectum do not exist and it might be a metastatic focus of occult SCC of other sites or squamous degeneration of pre-existing adenocarcinoma, but this opinion has not been widely accepted. The current hypothesis is that Ad-SCC and SCC of the colon and rectum belong to the same entity and the squamous epithelial components have more invasive power than glandular components.…”

Squamous cell carcinoma of the rectum: The treatment paradigm

“…Although some authors are not sure it exists, 3 over the years, four hypotheses have developed to explain the physiopathology of squamous cell carcinoma of the rectum: 1) squamous metaplasia resulting from inflammation or irritation secondary to infection, 4,5 radiation 6 or inflammatory bowel disease 7e9 ; 2) possibility of pluripotent stem cells capable of squamous differentiation 10,11 ; 3) malignant transformation of epithelial damage 12 ; 4) malignant transformation of preexisting adenomas. 13 Diagnostic criteria for squamous cell carcinoma of the rectum were established by Williams et al 14 and included: absence of any anal canal extension, absence of fistulous tract, absence of evidence of metastasis. Because the low incidence of the disease, only case reports 4,6,9,12,13,15,16,21e27 and small case series 2,10,17e20,32 have been reported in literature, since Rainford, 15 in 1933, had described the first case of squamous cell carcinoma involving the rectum.…”

Squamous cell carcinoma of rectum presenting in a man: a case report

“…These can be summarized as: (A) Proliferation of uncommitted basal cells into squamous cells which undergo malignant transformation following mucosal injury [15]; (B) Ability of pluripotent stem cells to undergo spontaneous squamous differentiation [16]; (C) Squamous metaplasia of glandular epithelium resulting from chronic inflammation or irritation, secondary to inflammatory bowel disease [17], infection [18] or radiation [19]; (D) Origin from embryonal nests of ectodermal cells; and (E) Arousal of carcinomas from preexisting adenomas or adenocarcinomas [7,20]. …”