Other tumors
Inflammatory myofibroblastic tumor

Topic Completed: 1 January 2014

Revised: 19 March 2019

Copyright: 2003-2019, PathologyOutlines.com, Inc.

PubMed Search: Inflammatory myofibroblastic tumor[TIAB] spleen

Vijay Shankar, M.D.
Page views in 2018: 636
Page views in 2019 to date: 417
Cite this page: Shankar V. Inflammatory myofibroblastic tumor. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/spleeninflammatorypseudotumor.html. Accessed August 24th, 2019.
Definition / general
  • Uncommon lesion of uncertain origin
  • Also called inflammatory pseudotumor (IPT)
  • Rare; < 50 cases reported in adults in spleen; < 10 cases in children
  • More common in women
  • Associated with fever of unknown origin, splenomegaly or an incidental finding
  • Actual pathogenesis remains unknown
  • Possible factors include bacterial infection, neoplastic processes, vascular cause, immunological derangement
  • Some cases are EBV+
Clinical features
  • Most patients with splenic tumors presents with B symptoms including weight loss, fever and abdominal pain
  • May present with splenomegaly
  • Usually favorable prognosis
Radiology description
  • Solitary, relatively large, well circumscribed mass
Radiology images

Images hosted on other servers:

Diffuse and inhomogeneous enhancement

Hepatic and splenic lesions

Splenic mass

Hypodense mass

Splenic lesion

Hypoechoic lesion

PET scan

Case reports
  • Splenectomy is curative
Gross description
  • Variable size, up to 11 cm
  • Usually solitary but may be multinodular
  • Variegated color due to hemorrhage and necrosis
Gross images

Images hosted on other servers:

Splenectomy specimen

Multinodular borders

Well circumscribed,
centrally necrotic,
tan, fleshy mass

Microscopic (histologic) description
  • Involves splenic red pulp
  • Patterns are spindled, sclerotic, xanthogranulomatous or plasma cell granuloma
  • Variable lymphocytes (T cells), plasma cells, eosinophils, histiocytes, myofibroblast-like cells (may be follicular dendritic cells)
  • Often central coagulative necrosis and neutrophils, cholesterol formation, hemorrhage
Microscopic (histologic) images

Images hosted on other servers:

Various images

Smooth muscle actin



Positive stains
Negative stains
Differential diagnosis
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