logo logo
Search: Organ site Search: Tumor / Syndrome
WHO Classification of Tumours
Inflammatory cloacagenic polyp
Anus and anal canal


Inflammatory cloacagenic polyps, first described in 1981
Click to access Pubmed
Lobert PF, Appelman HD (1981)
Inflammatory cloacogenic polyp. A unique inflammatory lesion of the anal transitional zone.
Am J Surg Pathol 5: 761-6

, are commonly associated with mucosal prolapse and sometimes with haemorrhoids
Click to access Pubmed
Chetty R, Bhathal PS, Slavin JL (1993)
Prolapse-induced inflammatory polyps of the colorectum and anal transitional zone.
Histopathology 23: 63-7

Click to access Pubmed
Levey JM, Banner B, Darrah J, Bonkovsky HL (1994)
Inflammatory cloacogenic polyp: three cases and literature review.
Am J Gastroenterol 89: 438-41

. These polyps arise in the anal transitional zone (ATZ) and form a rounded or irregular mass measuring 15 cm in diameter. Histologically, the polyp consists of hyperplastic rectal mucosa, partly covered with ATZ-type or squamous epithelium. The surface is typically eroded and the stroma shows oedema, vascular ectasia, inflammatory cells and granulation tissue. Vertically oriented smooth-muscle fibres are found between the elongated and tortuous crypts. It can be confused with a prolapsed rectal adenoma
Click to access Pubmed
Parfitt JR, Shepherd NA (2008)
Polypoid mucosal prolapse complicating low rectal adenomas: beware the inflammatory cloacogenic polyp!
Histopathology 53: 91-6

Click for details
Bosman FT, Carneiro F, Hruban RH, Theise ND (Eds.)
WHO Classification of Tumours of the Digestive System.
4th Edition
International Agency for Research on Cancer: Lyon 2010


Topographic definition of the anal canal, anal margin and perianal region