Metaphyseal fibrous defect

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Metaphyseal fibrous defect, abbreviated MFD, is a common benign abnormality of the metaphysis, classically seen in children and young adults.

Metaphyseal fibrous defect
Diagnosis in short

Synonyms nonossifying fibroma, fibrous cortical defect, fibrous metaphyseal defect, fibroxanthoma of bone
LM DDx giant cell tumour of bone
Site metaphysis of bone - usu. lower extremity

Clinical history incidental radiograhic finding
Prevalence common
Radiology lucent defect
Prognosis benign
Treatment none

They are also known as fibrous cortical defect, fibrous metaphyseal defect, and fibroxanthoma of bone. Nonossifying fibroma is a larger lesion but otherwise identical.

General

  • Common.
  • Non-neoplastic.
  • Self-limited.
  • Skeletally immature individuals, children and adolescents.
  • Often small lesions discovered as an radiographic incidentaloma.
  • Rarely seen as a pathologic specimen (should not be biopsied).
  • May be seen in the context of Jaffe-Campanacci syndrome.[1]

Clinical history:

  • Incidental radiographic finding.
  • Pathologic fracture.

Prognosis:

  • Ideally should not be biopsied.
  • Radiographically characteristic and benign.
  • Ideally should not be treated or even biopsied.
  • Spontaneously resolve by ossification.
  • May resolve into a 'bone island'.

Site

  • Metaphysis of distal femur or proximal tibia (80%).
  • Cortical.
  • Metaphysis.
  • Long bones.
  • Eccentric location.

Gross

  • Firm, granular, brown to yellow to red.

Microscopic

Features:

  • Spindle cells without cytologic atypia are arranged in a storiform pattern.
  • Scattered chronic inflammatory cells and benign giant cells.
  • Foam cells and hemosiderin deposition are present.
  • Mitoses are seen but cytologic atypia is absent.

DDx (microscopic):

Relevant Diagnostic Groups

  • Clinical
    • FOG MACHINES - acronym for radiographically lytic bone lesions [2]
    • 'Skeletal do not touch list' [3]
  • Pathologic
    • Giant cell lesions of bone.
    • Spindle cell lesions of bone.

Images

www:

Stains

  • Not relevant.

IHC

  • Not relevant

Molecular

  • Not relevant

Radiographic findings

Sharply demarcated, lucent, loculated, meta-diaphyseal lesion surrounded by a rim of sclerotic bone

Sign out

BONE, CURETTAGE: METAPHYSEAL FIBROUS DEFECT / NONOSSIFYING FIBROMA.

See also

References

External links