Benign lesions / conditions
Inflammatory pseudotumor

Authors: Komal Arora, M.D. (see Authors page)

Revised: 28 July 2016, last major update July 2012

Copyright: (c) 2003-2016,, Inc.

PubMed search: prostatic inflammatory pseudotumor
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Cite this page: Inflammatory pseudotumor. website. Accessed January 22nd, 2019.
Definition / general
  • Also called pseudosarcomatous fibromyxoid tumor, inflammatory myofibroblastic tumor
  • Similar to postoperative spindle cell nodule but without history of TURP
  • Rare, resembles sarcoma or sarcomatoid carcinoma (Hum Pathol 1993;24:1203)
  • Diploid, low S phase fraction
  • Benign behavior
Case reports
Microscopic (histologic) description
  • Myxoid lesions, proliferation of slightly atypical spindle fibroblastic cells in a background of granulation tissue-type vascularity and inflammatory cells
  • Rare mitoses, no atypical mitoses
Microscopic (histologic) images

Images hosted on other servers:

Various images

Positive stains
  • Vimentin, smooth muscle actin, CD68 (in histiocytes)
Negative stains
  • S100, desmin, myoglobin, keratin
Electron microscopy description
  • Fibroblastic and myofibroblastic cell features