Testis and epididymis
Nonneoplastic lesions
Hernia sac with mesothelial entrapment

Author: Rafael Jimenez, M.D. (see Authors page)

Revised: 9 June 2017, last major update March 2012

Copyright: (c) 2003-2017, PathologyOutlines.com, Inc.

PubMed Search: Hernia sac entrapment
Table of Contents
Definition / general
Cite this page: Hernia sac with mesothelial entrapment. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/testisherniasacepid.html. Accessed December 16th, 2017.
Definition / general
  • Vas deferens or epididymis may become entrapped in hernia sacs and subject to inadvertent transection, particularly in children
  • One study of 7314 boys with herniorrhaphy demonstrated 0.23% with vas deferens, 0.30% with epididymis (Am J Surg Pathol 1999;23:880)
  • Inclusions in hernia sacs may resemble vas deferens, with single or separate gland like structures lined by pseudostratified columnar epithelium with luminal cilia and an encircling stromal coat, may be embryonic remnants
    • Vas deferens is CD10+; stromal coat > 1.0 mm (even in prepubertal boys), histologically similar inclusions are CD10 negative, stromal coat < 0.8 mm but may be CD10+ (Am J Surg Pathol 2003;27:469)
  • Inclusions in hernia sacs may also resemble epididymis, with closely arranged clusters of numerous tubules lined by low cuboidal epithelium, with occasional ovoid cells with clear cytoplasm resembling "peg cells," may be embryonal remnants
    • May be difficult to differentiate CD10+ epididymis from those inclusions that are also CD10+ (some inclusions are CD10-, Am J Surg Pathol 2003;27:469)
  • Note: reactive mesothelial hyperplasia in a hernia sac may mimic mesothelioma
  • Additional references: Hum Pathol 1990;21:339