Prostate gland & seminal vesicles

Benign mimickers of carcinoma

Sclerosing adenosis

Topic Completed: 1 November 2015

Minor changes: 4 September 2020

Copyright: 2003-2020,, Inc.

PubMed Search: Sclerosing adenosis [title] prostate

Andres Matoso, M.D.
Page views in 2020: 1,863
Page views in 2021 to date: 1,363
Cite this page: Matoso A. Sclerosing adenosis. website. Accessed December 8th, 2021.
Definition / general
  • A mixture of well formed glands, usually very small, in a background of very cellular stroma composed of spindle cells
Essential features
  • Sclerosing adenosis is a benign proliferation of small well formed glands, similar to adenosis but with prominent cellular spindle cell stroma
  • The stroma displays a characteristic myxoid appearance
  • Rare finding in ~2% of radical prostatectomy specimens, more frequent in TURP specimens
  • Historically designated as adenomatoid prostatic tumor, but the term sclerosing adenosis is preferred as it is unrelated to adenomatoid tumor of other sites
  • More frequently seen in TURP specimens, but occasionally seen in needle biopsies
  • One series reported it in 2% of radical prostatectomies
  • Central zone of the prostate
Clinical features
  • The only clinical relevance is that it may be confused with prostatic adenocarcinoma
  • The glands of sclerosing adenosis display cells with clear or amphophilic cytoplasm and nuclei without prominent nucleoli
  • Basal cell layer can be seen in H&E stained slide or highlighted with basal cell markers
Case reports
Positive stains
Electron microscopy description
Differential diagnosis
  • Adenocarcinoma of the prostate is the main differential diagnosis; in contrast to carcinoma, sclerosis adenosis shows a basal cell layer
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