Stromal tumors
Inflammatory myofibroblastic tumor

Topic Completed: 1 August 2011

Revised: 25 February 2019

Copyright: 2002-2017, PathologyOutlines.com, Inc.

PubMed search: uterus "inflammatory myofibroblastic tumor"
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Cite this page: Desouki M. Inflammatory myofibroblastic tumor. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/uterusinflammpseudo.html. Accessed May 23rd, 2019.
Definition / general
  • The term "inflammatory pseudotumor" is applied to a variety of neoplastic and nonneoplastic entities, characterized by a collection of lymphocytes, plasma cells and neutrophils forming a well circumscribed mass
  • Also includes inflammatory myoblastic tumors with distinct clinical, pathological and molecular features, which is now the preferred terminology
  • Inflammatory pseudotumor (IPT), inflammatory myoblastic tumor (IMT)
  • Younger age than other uterine tumors
  • All locations
  • May be preceded by an acute infection and represent an immunologic reparative response or a low grade spindle cell fibrosarcoma
Clinical features
  • May present with unexplained fever, abdominal pain, anorexia and weight loss
  • On pelvic examination, the uterus may be bulky and tender with restricted mobility giving the impression of "frozen pelvis"
  • Laboratory findings: elevated ESR and serum immunoglobulins, thrombocytosis and anemia
Prognostic factors
  • IPTs may recur locally but do not metastasize
  • IMTs have intermediate biological potential for local recurrence and distant metastasis
  • Mortality rate of 7%
  • Surgical excision is curative in 90% of cases
  • Antibiotic therapy may be useful
Gross description
  • Circumscribed mass
Microscopic (histologic) description
  • Mixture of spindle cells exhibiting storiform pattern together with numerous lymphocytes, plasma cells and histiocytes
  • In part, a diagnosis of exclusion
Cytology description
  • Fine needle aspiration may demonstrate inflammatory epitheloid granuloma
Positive stains
Differential diagnosis
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