Osteofibrous dysplasia

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==General== [1]

  • Rare, benign fibro-osseous lesion
Template:Osteofibrous dysplasia
Diagnosis in short
  • Alternate names
    • Congenital osteitis fibrosa
  • Location
    • Cortex of the tibial diaphysis
  • Pathophysiology
    • May be either a clonal neoplastic lesion or a developmental dysplasia.
    • May be related to adamantinoma
  • Presentation
    • Lower leg swelling
    • Pain
    • Tibial bowing
  • Radiology
    • Intracortical lytic lesion
    • Surrounding zone of sclerosis
    • Seldom progresses radiologically
  • Clinical DDX
    • Adamantinoma - usually older (teens-twenties), may have soft tissue extension
    • Metaphyseal fibrous defect - metaphyseal location
    • Fibrous dysplasia
  • Prognosis
    • Self limited
  • Population
    • Children
    • First 2 decades of life
    • Median 9.5 years

Gross

Microscopic

The lesion has a zonal architecture with a center of immature bone surrounded by more mature lamellar bone. The central spicules of woven bony trabeculae are lined by a layer of osteoblasts. The backgound is a loose and storiform fibrous tissue.

  • Histologic DDX
    • Adamantinoma - epithelial elements are prominent and atypical
    • OFD-like adamantinoma (see below)
    • Fibrous dysplasia - Bony trabeculae lack osteoblastic rimming, not zonal
  • Tips
    • Current discussion regarding the definition of an OFD-like adamantinoma.
      • WHO as of 2010 required absence of keratin-positive cells for OFD
      • Some accept as OFD lesions with scattered isolated keratin positive spindled cells.
      • Gray zone and varying interpretations of the boundry of OFD, OFD-like adamantinoma and adamantinoma.
    • The diagnosis depends on the ratio of fibrous to epithelial tissue which can vary within each particular tumor.
    • Therefore, ample tissue is required for accurate histologic diagnosis

Images

Stains

Not relevant

IHC

Keratin positive isolated cells accepted by some.

Molecular

Clonal chromosomal abnormalities

    • Trisomies of chromosomes 7, 8, 12,21, and/or 22

Sign out

BONE; CURRETTAGE: OSTEOFIBROUS DYSPLASIA.

See also

References