Inflammatory myofibroblastic tumor of bone: report of two cases with evidence of clonal chromosomal changes

Am J Surg Pathol. 1997 Oct;21(10):1166-72. doi: 10.1097/00000478-199710000-00006.


Inflammatory myofibroblastic tumor (inflammatory pseudotumor) is a pseudosarcomatous lesion that is recognized with increasing frequency in various anatomic locations. However, this lesion has not been previously reported in bone. We report on two cases of inflammatory myofibroblastic tumor occurring in bone in young adults. Both tumors presented as slightly painful, osteolytic, and well-delineated lesions of the distal femur, with a hyperintense signal on T2-weighted magnetic resonance imaging. The patients had an uneventful recovery after curettage. The follow-up time was 11 months for both patients, and no recurrence was noted. On histologic examination, the lesions were characterized by collagen-rich and generally poorly cellular tissue containing spindled to plump (myo)fibroblast-like cells and a variable admixture of inflammatory cells. Focal calcifications and reactive bone formation were present. Clonal, albeit different, chromosomal changes were found in both cases (47,XY,-9,-12,add(21)(q21),+der(?)t(?;9)(?;q11), +mar,+r and 47, XY, +r/47, idem, add(12)(p13)). The present and other reported cytogenetic findings suggest that inflammatory myofibroblastic tumors could well be neoplastic.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Bone Diseases / diagnostic imaging
  • Bone Diseases / genetics
  • Bone Diseases / pathology*
  • Chromosome Aberrations
  • Chromosome Disorders
  • Chromosomes, Human, Pair 12
  • Chromosomes, Human, Pair 21
  • Chromosomes, Human, Pair 3
  • Chromosomes, Human, Pair 9
  • Genetic Markers
  • Granuloma, Plasma Cell / diagnostic imaging
  • Granuloma, Plasma Cell / genetics
  • Granuloma, Plasma Cell / pathology*
  • Humans
  • In Situ Hybridization
  • Knee Joint / diagnostic imaging
  • Knee Joint / pathology
  • Magnetic Resonance Imaging
  • Male
  • Tomography, X-Ray Computed


  • Genetic Markers