Prostate gland

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The prostate gland and its surrounding structures. (WC/NCI)

The prostate gland adds juice to the sperm. In old men it creates a lot of problems... nodular hyperplasia (commonly called BPH or benign prostatic hyperplasia) and cancer (usually adenocarcinoma).

Prostate cancer is such a big topic it is dealt with in its own article.

The female homologue of the prostate gland is considered to be Skene's gland.[1]

Normal prostate gland

Anatomy

Divided into three zones:[2]

  1. Peripheral zone - posterior aspect, palpable with digit.
  2. Central zone - considered resistant to disease.
  3. Transition zone - usual location for nodular hyperplasia.

Histology

  • Glands have two cell layers (similar to glands in breast).
    • Second cell layer may be difficult to see (like in breast).
  • Epithelium in glands is "folded" or "tufted".
    • Very important - helps to differentiate from Gleason pattern 3.
  • Luminal epithelium often clear cytoplasm.
  • Single nucleus.

Benign normal:

  • Corpora amylacea.
    • Round/ovoid-eosinophilic bodies -- with laminations (layered appearance).
    • In gland lumina.
    • Usually in benign glands - but cannot be used to exclude cancer.[3]
    • Very common.
    • These should be differentiated from eosinophilic proteinaceous debris - which is associated with cancer.

Negatives:

  • No nucleoli present (if you see nuclei think: cancer, HGPIN, reactive changes, basal cell hyperplasia).
  • No mitoses - these are uncommon... even in high grade prostate cancer.

Notes:

Images

IHC of normal prostate

Normal prostate:

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Staining slightly abnormal - morphology not definitely abnormal

COMMENT:
Very focal AMACR staining is seen; this is interpreted as negative, in the
context of no definite cytologic changes.  The basal cells appear to be 
preserved in all of the tissue sampled.

Compatible with previous biopsy

COMMENT:
Siderophages are seen in several cores; this is compatible with the history 
of a previous biopsy.

Other accessory glands

Bulbourethral gland

  • AKA Cowper's gland.

Seminal vesicles

Specimens

Approach

  • Know the common diagnoses well.
  • Core biopsies - scan the slides with the 10x objective.

Common diagnoses

  • Benign.
    • Atrophy - may resemble adenocarcinoma - typically not reported.
    • Adenosis - may resemble adenocarcinoma - typically not reported.
  • Prostate adenocarcinoma.
  • HGPIN (high-grade prostatic intraepithelial neoplasia) - prostate adenocarcinoma precursor lesion.
  • ASAP (atypical small acinar proliferation) - used if you have a few abnormal appearing glands... but can't decide between prostate adenocarcinoma & benign.
  • Chronic inflammation.
  • Acute inflammation - can result in an elevated PSA and may have prompted the biopsy you're looking at.
  • Nodular hyperplasia of the prostate; AKA benign prostatic hypertrophy (BPH).
    • Not diagnosed on needle biopsies.
    • BPH is technically incorrect -- the process is a hyperplasia.
      • Hyperplasia = proliferation of cells, hypertrophy = enlargement of cells.
        • How to remember? A. Prostate... hyperPlasia.

Clinical history

  • PSA (serum).
    • >10 ng/mL worrisome for prostate cancer.
    • Normal is age dependent - increases with age, usu. cut-off ~ 4 ng/mL.
  • HIFU = High Intensity Focused Ultrasound - an ablation procedure for prostate cancer.[6]

Benign changes and remnants

Adenosis of the prostate gland

  • AKA atypical adenomatous hyperplasia of the prostate gland (or atypical adenomatous hyperplasia).

Basal cell hyperplasia of the prostate

Atrophy of the prostate

  • AKA atrophy.
  • AKA prostatic atrophy.
  • AKA atrophy of the prostate gland.

Mesonephric remnant of the prostate gland

Benign conditions

Prostatic nodular hyperplasia

  • AKA nodular hyperplasia of the prostate.
  • AKA benign prostatic hyperplasia (abbreviated BPH).
  • AKA benign prostatic hypertrophy.
    • This is a misnomer. It is not a hypertrophy.

Acute inflammation of the prostate gland

Prostate gland
External resources
EHVSC 10176
  • AKA prostate gland with acute inflammation.

General

  • A may lead to an increase in the PSA and prompt biopsy.

Note:

  • "Prostatitis" is considered a clinical diagnosis.
    • Cases are signed out as "acute inflammation".
      • Some pathologists do not comment on the presence (or absence) of inflammation.

Microscopic

Features:

  • Neutrophils within the glands, between the epithelial cells or within the stroma - key feature.
  • +/-Chronic inflammation (lymphocytes) within the surrounding stroma.

DDx:

Image

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G. PROSTATE, LEFT LATERAL SUPERIOR, BIOPSY:
- BENIGN PROSTATE TISSUE;
- FOCAL ACUTE INFLAMMATION. 
G. PROSTATE, LEFT LATERAL SUPERIOR, BIOPSY:
- BENIGN PROSTATE TISSUE;
- FOCAL ACUTE AND CHRONIC INFLAMMATION. 

Chronic inflammation not otherwise specified

General

  • Common.
  • Non-specific finding.
  • Etiology usually not apparent on histomorphology.

Microscopic

Features:

  • Lymphocytes within the glands, between the epithelial cells or within the stroma - key feature.

Notes:

  • Rare scattered lymphocytes are common, especially in the central portion of the gland.
  • "Focal" one field with a 2.2 mm diameter involved.

Image

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G. PROSTATE, LEFT LATERAL SUPERIOR, BIOPSY:
- BENIGN PROSTATE TISSUE;
- FOCAL CHRONIC INFLAMMATION. 
F. PROSTATE, RIGHT MEDIAL MIDZONE, BIOPSY:
- BENIGN PROSTATE TISSUE;
- CHRONIC INFLAMMATION. 

Note:

  • Opinion is divided on whether this finding should be reported.
    • Advocates for reporting inflammation say "[i]t is just reporting what you see and may explain the bump in PSA."
    • Naysayers opine that "[i]t may provide false assurance that no cancer is present."

Granulomatous prostatitis

Prostatic infarct

General

Microscopic

Features:

  • Classic findings of necrosis:
    • Karyolysis (loss of nuclei), karyorrhexis (frag. of nuclei), pyknosis (small shrunken nuclei).
  • +/-Squamous metaplasia of prostate gland epithelium.

Notes:

  • Corpora amylacea - help... call it benign.
  • Glands maintain normal spacing.

DDx:

Image:

Preneoplastic changes and atypical changes

High-grade prostatic intraepithelial neoplasia

  • Abbreviated as HGPIN.
  • May be referred to as prostatic intraepithelial neoplasia, abbreviated PIN.

Atypical small acinar proliferation

  • Abbreviated ASAP.
  • AKA suspicious for carcinoma.[8]
    • ASAP is preferred as it does not contain the word carcinoma and, thus, cannot be misread as carcinoma, i.e. positive for malignancy.

Prostate cancer

This is a big topic that is dealt with in its own article.

See also

References

  1. Dodson, MK.; Cliby, WA.; Pettavel, PP.; Keeney, GL.; Podratz, KC. (Dec 1995). "Female urethral adenocarcinoma: evidence for more than one tissue of origin?". Gynecol Oncol 59 (3): 352-7. doi:10.1006/gyno.1995.9963. PMID 8522254.
  2. McNeal, JE. (Aug 1988). "Normal histology of the prostate.". Am J Surg Pathol 12 (8): 619-33. PMID 2456702.
  3. Christian JD, Lamm TC, Morrow JF, Bostwick DG (January 2005). "Corpora amylacea in adenocarcinoma of the prostate: incidence and histology within needle core biopsies". Mod. Pathol. 18 (1): 36–9. doi:10.1038/modpathol.3800250.
  4. Trpkov, K.; Bartczak-McKay, J.; Yilmaz, A. (Aug 2009). "Usefulness of cytokeratin 5/6 and AMACR applied as double sequential immunostains for diagnostic assessment of problematic prostate specimens.". Am J Clin Pathol 132 (2): 211-20; quiz 307. doi:10.1309/AJCPGFJP83IXZEUR. PMID 19605815.
  5. URL: http://www.cancer.gov/dictionary?cdrid=446218. Accessed on: 23 February 2012.
  6. URL: http://www.internationalhifu.com/what-is-hifu-mainmenu-132.html. Accessed on: 15 June 2010.
  7. 7.0 7.1 Milord, RA.; Kahane, H.; Epstein, JI. (Oct 2000). "Infarct of the prostate gland: experience on needle biopsy specimens.". Am J Surg Pathol 24 (10): 1378-84. PMID 11023099.
  8. THvdK. 19 June 2010.