Prostate gland & seminal vesicles
Benign mimickers of carcinoma
Basal cell hyperplasia

Topic Completed: 1 April 2016

Minor changes: 3 September 2020

Copyright: 2002-2020,, Inc.

PubMed Search: Prostate Basal cell hyperplasia[title]

Andres Matoso, M.D.
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Cite this page: Matoso A. Basal cell hyperplasia. website. Accessed October 29th, 2020.
Definition / general
  • Basal cell hyperplasia is the expansion of the basal cells within the prostatic acini
  • May mimic prostate adenocarcinoma when prominent nucleoli are present
Essential features
  • May be arranged in small crowded glands, often back to back forming pseudocribriform glands
  • Solid nests can be seen frequently
  • Scant cytoplasm, prominent nucleoli
  • Can show coarse calcifications or eosinophilic (hyaline) cytoplasmic globules
  • Also called fetalization of the prostate, embryonal hyperplasia and atypical basal cell hyperplasia (term no longer used)
  • Florid basal cell hyperplasia: extensive proliferation of basal cells involving > 100 small crowded acini (per section) forming a nodule (Hum Pathol 2005;36:480)
  • Nodule formation has been termed basal cell adenoma or adenoid basal cell tumor (terms not recommended)
  • Adults
  • More common in the transition zone; can be present in the peripheral zone
  • Although more common in TURP specimens, can also be seen in needle biopsies and radical prostatectomies
Prognostic factors
  • Not associated with adverse prognosis or higher risk of cancer
Microscopic (histologic) description
  • At low magnification, basal cell hyperplasia is characterized by a basophilic appearance
  • Cells have scant cytoplasm, blue nuclei and prominent nucleoli
  • Can form solid nests, back-to-back glands, pseudocribriform glands
  • Intracytoplasmic eosinophilic inclusions (53%)
  • Microcalcifications (40%)
  • Intraluminal amorphic secretions
  • No crystalloids
  • Florid: extensive proliferation of basal cells involving > 100 small crowded acini (per section) forming a nodule (Hum Pathol 2005;36:480)
Microscopic (histologic) images

Contributed by Andres Matoso, M.D.
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Florid basal cell hyperplasia

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Basal cell carcinoma

Positive stains
Negative stains
Differential diagnosis
  • High grade prostatic intraepithelial neoplasia: basal cells are not easily identifiable. HGPIN nuclei are columnar while basal cell hyperplasia nuclei are rounded. PIN glands are in general larger than glands in basal cell hyperplasia
  • Prostate adenocarcinoma: carcinoma is negative for HMWCK and p63 and positive for AMACR, while basal cell hyperplasia is positive for HMWCK and p63 and negative for AMACR
  • Basal cell carcinoma: Carcinoma is characterized by different sizes nests, adenoid cystic pattern, center of nest lined by eosinophilic cells, stron bcl-2 immunostaining and > 20% Ki67 positive cells
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