Prostate gland & seminal vesicles

Acinar / ductal adenocarcinomas

Acinar adenocarcinoma

Pseudohyperplastic pattern

Last author update: 1 March 2012
Last staff update: 21 November 2023

Copyright: 2003-2024,, Inc.

PubMed search: prostatic pseudohyperplastic adenocarcinoma

Komal Arora, M.D.
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Cite this page: Arora K. Pseudohyperplastic pattern. website. Accessed February 22nd, 2024.
Definition / general
  • Rare carcinoma that resembles benign hyperplastic glands
  • Difficult to grade
  • Epstein recommends deferring to the grade of the associated usual type adenocarcinoma in the radical prostatectomy specimen, which is often Gleason score 5-7
  • False negative diagnostic rate was 1.3% for TURP specimens (Pseudo Oncol Res 2003;9:232)
  • 60% of tumor has benign architectural but malignant nuclear features (Am J Surg Pathol 2000;24:1039)
Case reports
Microscopic (histologic) description
  • Papillary infoldings (100%), crowded glands, large atypical glands (95%), nuclear enlargement (95%), pink amorphous secretions (70%), occasional to frequent nucleoli (45%), branching (45%), crystalloids (45%), corpora amylacea (20%); at low power, transition to typical, small acinar adenocarcinoma may be helpful (Am J Surg Pathol 1998;22:1239)
  • With core needle biopsy, only diagnostic clue may be a subtle disruption of the normal glandular - stromal relationship (Mod Pathol 2004;17:307, Am J Surg Pathol 2010;34:35)
  • Despite its benign appearance, may be associated with intermediate grade cancer and can exhibit aggressive behavior
Microscopic (histologic) images

Case #117

Various images

Triple stain (AMACR, p63, HMWK)

Positive stains
Negative stains
  • High molecular weight keratin and p63 show absence of basal cells in hyperplastic glands (normal glands serve as positive control)
Differential diagnosis
  • Adenosis, high grade PIN (not as crowded or infiltrative), benign hyperplasia
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