Group

Non-ossifying Fibromas (NOF)

A non-ossifying fibroma (NOF) is a common benign (non-cancerous) bone lesion that occurs in children and adolescents. It is made up of fibrous tissue rather than normal bone and is usually discovered incidentally on X-rays.

It is also sometimes called a fibrous cortical defect when it is smaller.

What causes it?

The exact cause is not fully understood, but NOFs are considered:

• Developmental abnormalities of bone formation

• Not caused by infection or cancer

• Not inherited in most cases