Non Ossifying Fibroma

Non ossifying fibroma (NOF) are fibrous defects in cortical area of long bones.

It is common in children and adolescents (high incidence in 4 – 8 years) with male to female ratio of 2:1.

Common sites are metaphysis are of long bones, commonly lower limbs.

What is the cause for NOF?

Etiology of NOF is Unknown. It is postulated to occur secondary to developmental defect.

How is NOF Identified ?

Clinically, majority of NOF are asymptomatic and are incidental findings.

Typically, a child presents with history of pain after playing and a plain radiograph shows a lesion involving cortex of metaphysis are of long bone not far from site of pain. This pain is temporary in nature can be localized to area near to lesion. Swelling or edema is uncommon.

A plain radiograph is sufficient to diagnose NOF. An MRI can be performed if other diagnosis is suspected, but is rarely done.

How is NOF managed ?

Majority of NOF require conservative management as they regress spontaneously.

Observation with serial follow up every 6 months is required only if the lesion is suspected to be growing or involves more than 50 % or bone diameter.

Pathological fracture is rare, if noticed can be treated with brace or cast immobilization depending on the bone involved.

Rarely, large NOF’s in weight bearing region with pain predominant symptom benefit from biopsy followed by a curettage and bone grafting or stabilisation.