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Anus and perianal area

Benign or non-neoplastic lesions

Inflammatory cloacogenic polyp

Reviewer: Nat Pernick, M.D. (see Reviewers page)
Revised: 15 April 2013, last major update April 2005
Copyright: (c) 2003-2013, PathologyOutlines.com, Inc.


● Middle aged patients with rectal bleeding
● Single or multiple polyps in anal canal, resemble hemorrhoids
● Associated with solitary rectal ulcer syndrome or mucosal prolapse; may be due to prolapse with ischemic damage and subsequent repair
● Patients may also have HPV related disorders


● Excision

Gross description

● Sessile, 1-2 cm

Micro description

● Tubulovillous with elongated, irregular crypts extending into submucosa (resembles colitis cystica profunda)
● Squamous, colorectal or transitional epithelium, eroded at surface or covered with exudates (Am J Surg Pathol 1981;5:761)
● May be hyperplastic or regenerative
● Thickened muscularis mucosa with irregular strands penetrating lamina propria
● No dysplastic changes, no desmoplasia, no invasion

Micro images

Left: H&E shows eroded surface epithelium, inflammatory cells in lamina propria, irregular glands with reactive epithelial changes, slips of smooth muscle surround many glands, right: PCNA shows widespread immunoreactivity

Low power

Contributed by Dr. Yvonne Bury, University Hospital of North Durham (UK)

Differential diagnosis

Villous adenoma

End of Anus and perianal area > Benign or non-neoplastic lesions > Inflammatory cloacogenic polyp

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