Prostate
Microscopic mimics of prostatic carcinoma
Sclerosing adenosis

Author: Andres Matoso, M.D. (see Authors page)

Revised: 13 November 2015, last major update November 2015

Copyright: (c) 2003-2015, PathologyOutlines.com, Inc.

PubMed Search: Sclerosing adenosis [title] prostate
Cite this page: Sclerosing adenosis. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/prostatesclerosingadenosis.html. Accessed December 6th, 2016.
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
Terminology
  • Historically designated as adenomatoid prostatic tumor, but the term sclerosing adenosis is preferred as it is unrelated to adenomatoid tumor of other sites
Epidemiology
  • More frequently seen in TURP specimens, but occasionally seen in needle biopsies
  • One series reported it in 2% of radical prostatectomies
Sites
  • Central zone of the prostate
Clinical Features
  • The only clinical relevance is that it may be confused with prostatic adenocarcinoma
Diagnosis
  • 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
Micro Images
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Variably sized glands

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Dense spindle stroma

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Poorly formed glands

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Pale acini

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Intraluminal blue mucin

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HMW cytokeratin

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S100+

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Smooth muscle actin

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Proliferation of irregular glands

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