Anus & perianal area


Paget disease

Editorial Board Member: Xiaoyan Liao, M.D., Ph.D.
Deputy Editor-in-Chief: Aaron R. Huber, D.O.
Raul S. Gonzalez, M.D.

Last author update: 30 May 2023
Last staff update: 30 May 2023

Copyright: 2002-2023,, Inc.

PubMed Search: Paget disease

Raul S. Gonzalez, M.D.
Page views in 2022: 2,135
Page views in 2023 to date: 1,527
Cite this page: Gonzalez RS. Paget disease. website. Accessed June 2nd, 2023.
Definition / general
  • Intraepithelial tumor usually of apocrine or possibly eccrine gland origin
Essential features
  • Intraepidermal neoplastic cells, sometimes linked to anal malignancy (secondary) but may also be primary disease
  • More common in older patients
  • Most associated malignancies are adenocarcinoma but pagetoid spread of other carcinoma types can occur
  • Primary Paget disease: no association with underlying invasive malignancy
  • Secondary Paget disease: related to intraepithelial spread of invasive malignancy
ICD coding
  • ICD-10: C21.0 - malignant neoplasm of anus, unspecified
  • Primary extramammary anal Paget disease is rare
  • Men and women are equally affected
  • Most often occurs in the fifth to seventh decade
  • Typically indolent but often recurs
  • Up to 40% of patients with anal Paget disease have secondary disease (associated with an underlying malignancy); usually adenocarcinoma but sometimes other forms, such as neuroendocrine carcinoma (Colorectal Dis 2023 Mar 21 [Epub ahead of print], Pathol Int 2004;54:630)
  • Arises anywhere between the dentate line and the perianal skin
  • Tissue sampling
Case reports
Clinical images

Images hosted on other servers:
Extensive perianal Paget disease, perineum

Extensive perianal Paget disease, perineum

Early response

Early response

Notable telangiectasia and fibrosis

Notable telangiectasia and fibrosis

Gross description
  • Erythematous, ulcerated or eczematous plaques or patches
Microscopic (histologic) description
  • Large, pale staining to clear intraepidermal neoplastic cells containing abundant mucin, arranged singly or occasionally in nests or gland-like formations
  • Cells are more numerous basally
  • Microscopic disease may extend beyond grossly visible changes
  • Associated changes include squamous hyperplasia, fibroepithelioma-like hyperplasia and papillomatous hyperplasia (Am J Surg Pathol 2000;24:543)
  • Pagetoid cells arising in association with a nonadenocarcinoma malignancy should have an appearance related to the causative malignancy (e.g., neuroendocrine carcinoma) (Pathol Int 2004;54:630)
Microscopic (histologic) images

Contributed by Raul S. Gonzalez, M.D.
Visible Paget cells

Visible Paget cells

Prominent intracytoplasmic mucin

Prominent intracytoplasmic mucin

Positive stains
Negative stains
Sample pathology report
  • Anus, biopsy:
    • Paget disease (see comment)
    • Comment: The cells are positive for CK7 by immunohistochemistry, confirming the diagnosis. Anal Paget disease sometimes arises in the setting of an invasive anal malignancy. Further clinical workup may be indicated.
Differential diagnosis
Board review style question #1

Which of the following is true about the anal lesion shown in the image above?

  1. It always occurs alongside adenocarcinoma
  2. It arises secondary to treatment for malignancy
  3. It is positive for CK7 and mucicarmine
  4. It only occurs in men
Board review style answer #1
C. Anal Paget disease is positive for CK7 and mucicarmine. It is often but not always secondary, occurring alongside an invasive malignancy. It arises equally in men and women. Treatment related reactive changes may mimic Paget disease.

Comment Here

Reference: Anus & perianal area - Paget disease
Board review style question #2
What is the typical behavior of anal Paget disease?

  1. It can metastasize even in the absence of adenocarcinoma
  2. It is generally indolent but may recur
  3. It spontaneously regresses
  4. It will always progress to invasive adenocarcinoma
Board review style answer #2
B. Anal Paget disease is generally indolent but may recur. Fewer than half of anal Paget disease cases are associated with invasive malignancy. It does not itself metastasize but it does not spontaneously regress either.

Comment Here

Reference: Anus & perianal area - Paget disease
Back to top
Image 01 Image 02