Prostate gland & seminal vesicles

Benign mimickers of carcinoma

Atrophy


Editorial Board Member: Bonnie Choy, M.D.
Deputy Editor-in-Chief: Maria Tretiakova, M.D., Ph.D.
Kenneth A. Iczkowski, M.D.

Topic Completed: 9 August 2021

Minor changes: 9 August 2021

Copyright: 2003-2021, PathologyOutlines.com, Inc.

PubMed Search: Prostate atrophy [TIAB]

Kenneth A. Iczkowski, M.D.
Page views in 2020: 3,133
Page views in 2021 to date: 3,359
Cite this page: Iczkowski, K. Atrophy. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/prostateatrophy.html. Accessed December 3rd, 2021.
Definition / general
  • Atrophy and its less common subtype postatrophic hyperplasia often comprise small acini and are the most frequent histologic mimics of prostatic adenocarcinoma
Essential features
  • Very common microscopic finding: up to 75% of biopsies (Ann Diagn Pathol 2016;24:55)
  • Most frequent mimic of cancer (Am J Surg Pathol 2005;29:874)
  • When associated with fibrosis, the atrophic glands may appear infiltrative
  • Atrophy includes several histologic variants: simple, cystic, partial and postatrophic hyperplasia
  • Radiographic abnormalities have been described and serum prostate specific antigen (PSA) may be increased
  • Immunostains may help in the distinction from cancer but caution is needed in their interpretation
Terminology
  • Benign prostate tissue with atrophy
  • When associated with inflammation and increased Ki67 index, it has been termed proliferative inflammatory atrophy (PIA)
ICD coding
  • ICD-9: 602.2 - atrophy of prostate
  • ICD-10: N42.89 - other specified disorders of prostate
Epidemiology
  • Atrophy is a common incidental finding in prostate biopsy and prostatectomy and increases with age
Pathophysiology
Etiology
  • Increases with age
Diagnosis
  • Diagnosis is by prostate biopsy or transurethral resection
Laboratory
  • Atrophy correlates with serum total or free PSA elevation; for this reason, it may be desirable to report atrophy in a negative biopsy set (Abdom Imaging 2009;34:271)
Radiology description
Radiology images

Images hosted on other servers:

mpMRI findings, cystic atrophy

Prognostic factors
Treatment
  • Does not require treatment
Microscopic (histologic) description
  • 4 subtypes have been categorized (Am J Surg Pathol 2006;30:1281):
    • Simple atrophy:
      • Characterized by its basophilic appearance at low magnification
      • Glands may be crowded or back to back with little intervening stroma
      • When associated with sclerosed stroma, the glands may assume a more angulated shape and infiltrative appearance
    • Simple atrophy with cyst formation:
      • Ballooning large acinar spaces
    • Postatrophic hyperplasia (PAH):
      • Postatrophic hyperplasia also appears basophilic at low power but often surrounds a dilated duct and is arranged in lobules of crowded acini
      • Normally has more mitotic figures than adjacent nonatrophic glands
    • Partial atrophy:
      • In contrast to simple atrophy and postatrophic hyperplasia, acini have a pale appearance and nuclei are more spaced apart
Microscopic (histologic) images

Contributed by Kenneth A. Iczkowski, M.D.
Missing Image

Small acinar atrophy

Missing Image

Dilated acinar atrophy

Missing Image Missing Image

Red doesn’t equal cancer


Missing Image

Sclerosing adenosis

Missing Image Missing Image

Cancer mimicking atrophy

Positive stains
Negative stains
Sample pathology report
  • Prostate, biopsies:
    • Benign prostatic tissue with focal / multifocal / diffuse atrophy
Differential diagnosis
  • Must distinguish from the atrophic variant of prostatic adenocarcinoma, which has these features:
    • Less cytoplasm, dilated lumens, macronucleoli in the majority of cells and absence of basal cells
    • Infiltrative growth between benign glands without atrophy
    • Usually coexists with usual type adenocarcinoma
Board review style question #1
Which of the following is true of prostatic atrophy?

  1. It is a strong predictive finding for subsequent cancer detection
  2. It is characterized exclusively by a small acinar pattern
  3. It cannot be associated with increased serum prostate specific antigen (PSA)
  4. It has no characteristic radiologic findings
  5. It is mimicked by a variant of cancer
Board review style answer #1
E. Atrophy is mimicked by a variant of cancer, called the pseudoatrophic variant. Atrophy is not a predictor of subsequent cancer detection (answer A) and may even lessen the chances of eventual cancer. Atrophy is not exclusive to small acini (answer B) and large acinar (cystic) types exist. Atrophy sometimes can be associated with increased serum prostate specific antigen (PSA) (answer C). Atrophy may have certain characteristic radiologic findings (answer D).

Comment here

Reference: Prostatic atrophy
Board review style question #2

What does the red staining AMACR signal indicate?

  1. Lack of cytologic atypia rules out cancer, even when red AMACR signal is present
  2. It indicates that some of these acini are suspicious for cancer
  3. It indicates cancer
  4. It indicates high grade prostatic intraepithelial neoplasia
Board review style answer #2
A. This red signal is present in benign, nonatypical atrophic acini. Remember that AMACR / P504S can give false positive results and atrophy is one source of such results. The dual stain should be interpreted with caution, based on corresponding hematoxylin eosin findings. High grade PIN should be AMACR positive but would have atypia.

Comment here

Reference: Prostatic atrophy
Back to top
Image 01 Image 02