Colon tumor
Mesenchymal tumors
Inflammatory myofibroblastic tumor

Author: Charanjeet Singh, M.D. (see Authors page)

Revised: 4 January 2017, last major update April 2012

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

PubMed Search: Inflammatory myofibroblastic tumor [title] colon

Cite this page: Inflammatory myofibroblastic tumor. website. Accessed January 16th, 2017.
Definition / General
  • Also called inflammatory pseudotumor, inflammatory fibrosarcoma and plasma cell granuloma
  • Often a pediatric tumor, usually multifocal, associated with fever, weight loss, anemia, leukocytosis, thrombocytosis, high sedimentation rate and hypergammaglobulinemia (J Pediatr Surg 2001;36:169)
  • Benign, but may recur
Case Reports
Gross Description
  • Circumscribed
Gross Images

Images hosted on other servers:

2 year old boy with colonic mass causing anemia

35 year old man with mass involving muscularis propria

Micro Description
  • Spindle cells with abundant amphophilic cytoplasm
  • Variably prominent nucleoli, lymphoplasmacytic infiltrate with polyclonal plasma cells
  • Laminated or whorled fibrosis
  • May contain psammoma bodies if present in peritoneum
Micro Images

Images hosted on other servers:

Colonic mass

Not necessarily colon:

Inflammatory cells and spindle cells

CD117 negative

Positive Stains
Negative Stains
Molecular / Cytogenetics Description
  • Fluorescent in situ hybridization for t(2:5) or variants
Electron Microscopy Description
  • Myofibroblasts
Differential Diagnosis