Prostate gland & seminal vesicles

Benign mimickers of carcinoma

Cowper glands

Topic Completed: 1 July 2015

Minor changes: 29 October 2020

Copyright: 2003-2021,, Inc.

PubMed Search: Cowper's glands [title]

Andres Matoso, M.D.
Page views in 2020: 2,373
Page views in 2021 to date: 2,423
Cite this page: Matoso A. Cowper glands. website. Accessed December 8th, 2021.
Definition / general
  • Cowper glands are also called bulbourethral glands because they are located surrounding the bulbar portion of the urethra, outside of the prostate
  • Most commonly, they can be found in TURP specimens, but occasionally they may be seen in needle biopsies or in biopsies from urethral stricture
  • Bulbar urethra
  • They are the homologous of Bartholin glands in women
  • They secrete clear fluid prior to ejaculation that helps to lubricate the urethra and a small proportion of the fluid of the ejaculate
Microscopic (histologic) description
  • They are composed of mucinous acini arranged in a lobular pattern with intercalated ducts
  • When present in needle biopsies, they may resemble foamy gland prostate adenocarcinoma
  • They are surrounded by skeletal muscle, further mimicking cancer
  • They can be positive for prostate markers PSA, PSAP and NKX3.1
  • The correct diagnosis lies in recognizing the dual population of acini and ducts surrounded by skeletal muscle as opposed to benign prostatic glands
  • Immunohistochemistry for high molecular weight cytokeratin is positive in basal cells and can help in the differential diagnosis with prostate cancer
Microscopic (histologic) images

Contributed by Andres Matoso, M.D.
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Low power of Cowper glands

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Glands and skeletal muscle

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Positive stains
  • By immunohistochemistry, Cowper glands can be positive for prostate markers PSA, PSAP and NKX3.1
  • Special stains mucicarmin and PAS are also positive
Differential diagnosis
Additional references
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