Prostate
Microscopic mimics of prostatic carcinoma
Seminal vesicles / ejaculatory duct

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

Revised: 12 December 2015, last major update December 2015

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

PubMed Search: Seminal vesicle [AND] ejaculatory duct [title]
Definition / General
  • Seminal vesicles are a pair of glands located below the bladder and in connection with the base of the prostate
  • They have a tube-like shape and can be folded to form diverticuli or outpouchings within its wall
Essential Features
  • Seminal vesicle/ejaculatory duct epithelium shows nuclear atypia that is degenerative in nature; also yellow pigment in the cytoplasm
  • The outpouching from the seminal vesicle epithelium can give origin to clusters of small glands that mimic prostate cancer
  • The key to the differential diagnosis is in recognizing the degenerative nuclear atypia, the characteristic yellow pigment and the nearby seminal vesicle epithelium
Clinical Features
  • Seminal vesicles can be a source of overdiagnosis when present in prostate needle biopsy or TUR specimens
Micro Description
  • Seminal vesicle has thick muscular wall, complex mucosal folds, columnar and basal cells
  • Cytoplasm has large coarse golden yellow-brown lipofuscin / lipochrome granules
  • Columnar cells also have atypical appearing "monster" cells with prominent nuclear atypia and degenerative appearance, may contain hyaline globules (degenerative) (Am J Surg Pathol 1981;5:483)
  • Lipochrome pigment granules may be type 1 (coarse, golden yellow-brown, usually abundant, usually in seminal vesicle / ejaculatory duct epithelium) or type 2 (fine, gray-brown, or dark and scant, present in occasional prostate adenocarcinomas or normal prostate acini, Arch Pathol Lab Med 1999;123:1093, Hum Pathol 1995;26:1302)
Micro Images

Images hosted on PathOut server:

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Images courtesy of Andres Matoso, M.D.



Images hosted on Other servers:

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Small and medium-sized acini

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Atypical hyperchromatic nuclei

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Lipofuscin pigment

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High mag

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Highly atypical cells

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Complex papillary folds

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Scarce pigment granules

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Various images

Positive Stains
  • MUC6 and PAX2 are positive in seminal vesicles and negative in prostate glands
  • PSA and PSAP can be positive in both seminal vesicles and prostate glands
Differential Diagnosis
  • The main differential diagnosis is with prostate adenocarcinoma
    • The outpouching from the seminal vesicle epithelium can give origin to clusters of small glands that mimic prostate cancer
    • The key to the differential diagnosis is in recognizing the degenerative nuclear atypia, the characteristic yellow pigment and the nearby seminal vesicle epithelium; immunohistochemistry for MUC6 or PAX2 can help if necessary