Testis & paratestis

Nonneoplastic lesions

Inflammatory pseudotumor

Last author update: 1 December 2012
Last staff update: 23 April 2021

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PubMed Search: Paratesticular fibrous pseudotumor

Sean R. Williamson, M.D.
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Cite this page: Williamson S. Inflammatory pseudotumor. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisinflammatorypseudtumor.html. Accessed June 2nd, 2023.
Definition / general
  • Synonyms: chronic proliferative periorchitis, inflammatory pseudotumor, nodular and diffuse fibrous proliferation, paratesticular fibrous pseudotumor
  • Ages 7 - 95 years, peaks in 20's
  • Reactive fibrous mass, usually between testicular tunica layers; also involves epididymis and spermatic cord, associated with hydrocele, infection, trauma (Am J Surg Pathol 2010;34:569)
  • Some cases may be type of IgG4 associated sclerosing disease (Virchows Arch 2011;458:109, Hum Pathol 2012;43:2084)
Case reports
  • 22 year old man with collagen rich stromal tumor attached to testicular tunica albuginea (Hum Pathol 1990;21:866)
  • Excision
Gross description
  • Multinodular thickening of peritesticular tissue or discrete mass of firm white tissue up to 15 cm
  • May be an associated hydrocele or hematocele
Microscopic (histologic) description
  • Dense fibrous tissue, fibroblasts, inflammatory cells, dystrophic calcification
  • With time, cellularity decreases and fibrosis increases
  • Usually no necrosis, no pleomorphism, no / rare mitotic activity (Am J Surg Pathol 2010;34:569)
Positive stains
Negative stains
Differential diagnosis
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