Fact-sheet: Nonossifying fibroma - fibroxanthoma
Updated on 10/04/2019 at 9:43 AM
Note : 0/10
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Definition
Non-ossifying fibroma (> 2 cm)
- Corresponds to the same lesion as a cortical defect, but with a size > 2 cm for the fibroma
- Benign pseudotumor of connective tissue
- 30-40% of children
- 95% diagnosed before age 20, M>F
- 80% in the lower limbs (distal femur, tibia)
- Solitary (75%) or multiple (25%)
- Course toward regression and ossification
Clinical features
- Incidental finding, asymptomatic
- Pathologic fracture if > 5 cm
Radiography
Classic appearance: well-defined multilobulated osteolytic cortical lesion, with a soap-bubble appearance
- Metaphyseal location, eccentric, cortical
- Long axis parallel to that of the diaphysis
- Cortical origin not always evident in some cases due to size
- Well-defined margin
- Lesion becomes sclerotic during the regression phase
CT
- Multilobulated cortical osteolytic lesion surrounded by a dense peripheral rim
- Metaphyseal location, eccentric
- Long axis parallel to that of the diaphysis
- Well-defined margins
MRI
Peripheral T1 and PD hyposignal related to sclerosis, with intermediate central signal and T2 hypersignal
Nuclear medicine
At the end of growth, possible uptake on bone scintigraphy during the ossification phase
Management
"No touch lesion": no biopsy if typical
If atypical features or giant forms: MRI +/- curettage and biopsy
Differential diagnosis
- Chondromyxoid fibroma
- Osteofibrous dysplasia
