Prostate gland & seminal vesicles

Topic Completed: 1 July 2016

Minor changes: 25 February 2019

Copyright: 2002-2019,, Inc.

PubMed Search: Malakoplakia [title]

Kenneth A. Iczkowski, M.D.
Page views in 2019: 861
Page views in 2020 to date: 512
Cite this page: Iczkowski KA. Malakoplakia. website. Accessed August 12th, 2020.
Definition / general
  • A peculiar form of tissue reaction to bacterial infection, usually gram negative
  • Originates with an E. coli or Klebisella pneumoniae urinary tract infection
  • The host cells have a defect in lysosomal degradation of bacteria
  • Iron and calcium accumulate around undigested bacteria in macrophages, forming Michaelis-Gutmann bodies
  • Although it is mostly associated with bladder disease, the transition zone of the prostate may be involved (Int J Surg Pathol 2007;15:86)
  • Ages 47 +
Clinical features
  • Prostate enlarged on clinical examination, suggestive of carcinoma; may resemble carcinoma on MRI (Radiographics 2016;36:162) or ultrasound
  • 8 cases have been reported in which prostatic adenocarcinoma was associated with the malakoplakia (Ann Diagn Pathol 2016;22:33)
  • Von Kossa stain may be helpful in staining the calcium
Microscopic (histologic) description
  • Michaelis-Gutmann bodies are iron and calcium around a nidus of undigested bacteria
Microscopic (histologic) images

Contributed by Kenneth A. Iczkowski, M.D.

Michaelis-Gutmann bodies (arrows)

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Classic features of malakoplakia

Differential diagnosis
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