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Anus and perianal area

Benign or non-neoplastic lesions


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


● Dilated or thrombosed veins in hemorrhoidal plexus, within or external to anus
● Portal hypertension may cause severe bleeding due to increased portal venous pressure or possibly coagulation abnormalities
● Rarely associated with carcinoma, condyloma, Crohnís disease, dysplasia, granulomas, herpes, lymphoma, melanoma, syphilis (plasma cell infiltrate), tuberculosis, so examine specimens carefully
● Common finding of pagetoid dyskeratosis is likely due to trauma from prolapse (Arch Pathol Lab Med 2001;125:1058)
● Symptoms: bleeding, pain if thrombosed


● Causes: dependency or other processes causing deterioration of connective tissue and smooth muscle that anchor anal submucosal venous sinusoids, causing distal displacement of anal canal cushions
● Less commonly due to hepatic cirrhosis, pregnancy, rectal carcinoma, uterine leiomyoma


● Symptomatic, excision

Clinical images

Prominent prolapsed true (internal) hemorrhoids

Gross description

● Dilated thick walled vessels

Micro description

● Dilated thick walled submucosal vessels and sinusoidal spaces
● Also thrombi and reorganized vessels with florid papillary endothelial hyperplasia, adjacent hemorrhage, surface ulceration, inflammatory changes; mucosa may be squamous, colorectal or transitional
● Pagetoid dyskeratosis (pale cells in epidermis with premature keratinization, resembling Pagetís cells) in 68%, prominent in 22%

Micro images

Various images of pagetoid dyskeratosis

Virtual slides

External hemorrhoids

Dilated vascular channels filled with blood

End of Anus and perianal area > Benign or non-neoplastic lesions > Hemorrhoids

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