Paratesticular fibrous pseudotumor--an IgG4-related disorder?

Virchows Arch. 2011 Jan;458(1):109-13. doi: 10.1007/s00428-010-0995-4. Epub 2010 Oct 19.


Paratesticular fibrous pseudotumor (nodular periorchitis, inflammatory pseudotumor of the spermatic cord) is a rare, benign condition of unknown etiology characterized by solitary or multiple intrascrotal nodules composed of dense fibrous tissue with a variable, sometimes sparse inflammatory infiltrate. Based on certain similarities to other fibroinflammatory disorders characterized by infiltrates of IgG4-expressing plasma cells and recently subsumed under the heading of IgG4-mediated diseases, we investigated the plasma cell distribution and immunoglobulin isotypes in three cases of paratesticular fibrous and inflammatory pseudotumor. All three cases showed a high number of IgG4-positive plasma cells with an IgG4 to IgG ratio of 44-48%. This finding indicates that paratesticular fibrous pseudotumor might belong to the growing list of IgG4-related diseases, which by now includes such diverse entities as retroperitoneal fibrosis, sclerosing pancreatitis and cholangitis, Riedel's thyroiditis, or sclerosing sialadenitis.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Humans
  • Immunoglobulin G / metabolism*
  • Male
  • Middle Aged
  • Neoplasms, Fibrous Tissue / diagnosis
  • Neoplasms, Fibrous Tissue / immunology*
  • Neoplasms, Fibrous Tissue / pathology
  • Plasma Cells / metabolism
  • Plasma Cells / pathology
  • Sclerosis / immunology
  • Testicular Neoplasms / diagnosis
  • Testicular Neoplasms / immunology*
  • Testicular Neoplasms / pathology


  • Immunoglobulin G