Other tumors
Inflammatory myofibroblastic tumor

Author: Deepali Jain, M.D. (see Authors page)

Revised: 2 January 2018, last major update August 2012

Copyright: (c) 2002-2018,, Inc.

PubMed Search: Inflammatory myofibroblastic tumor pancreas

Cite this page: Jain, D. Inflammatory myofibroblastic tumor. website. Accessed November 21st, 2018.
Definition / general
  • Rare tumor (more common in lung) that may constrict bile duct
  • Cases with IgG4+ plasma cells perhaps should be classified separately as IgG4 related disorder, since they are distinct entities (Mod Pathol 2011;24:606)
Gross images

Images hosted on other servers:

19 year old man with cystic mass and splenic rupture

Microscopic (histologic) description
  • Spindled cells, collagen and variable lymphocytes and plasma cells
  • Rarely has prominent eosinophils
Microscopic (histologic) images

Images hosted on other servers:

Various images

19 year old man with cystic mass and splenic rupture

Left: bland spindle cells with lymphocytes and plasma cells (arrows) but no mitotic activity; right: smooth muscle actin

Loosely arranged spindle cells with admixed collagen bundles and scattered inflammatory infiltrate; proliferation extends into the adjacent fat and focal small lymphoid aggregates are present

Negative stains
Differential diagnosis
  • Follicular dendritic cell tumor
  • Inflammatory fibrosarcoma