A nonossifying fibroma is almost always asymptomatic and therefore usually an incidental finding on radiography.
The following symptoms and complaints may indicate a nonossifying fibroma (NOF):
- Uncharacteristic pulling pain (rare) – usually on the inside of the knee joint.
Localization
Typical for primary bone tumors is that they can be assigned to a characteristic localization in addition to a certain age range. They arise clustered at the sites of most intense longitudinal growth (metaepiphyseal/articular area).
The following questions should be answered by diagnostic measures:
- Localization in the skeleton → Which bone is affected?
- Localization in the bone → epiphysis* (joint end of the bone (near the joint)), metaphysis* (transition from epiphysis to diaphysis), diaphysis* (long bone shaft), central, eccentric (not central), cortical (at the solid outer shell of the bone), extracortical, intraarticular (within the joint capsule).
Non-osseous fibroma often occurs near the epiphysis (near the end of the joint), migrates with growth towards the metaphysis of the long tubular bones of the lower extremities (in 90% of cases) – femur (thigh bone) as well as tibia (shin bone) – and spreads to the medullary cavity of the bone.
* Example of the structure of a long bone: epiphysis – metaphysis – diaphysis – metaphysis – epiphysis.