Nonossifying fibroma developed in metaphysis and epiphysis--a case report.

Nonossifying fibroma is developed in childhood and adolescence and is usually asymptomatic. It is typically arises in the metaphysis of long bone and migrates toward the diaphysis with growth. We present a very rare case of nonossifying fibroma involving metaphysis and epiphysis of the distal femur in a 20-year-old man. Nonossifying fibroma is a benign fibroblastic lesion, which is also termed benign cortical defect and fibroxanthoma. A nonossifying fibroma rarely causes problems and does not interfere with healing or growth. The lesions are usually asymptomatic. With growth and remodeling of the bone, the lesion typically disappears and is replaced with normal bone. However, the lesion may weaken the involved bone, causing fracture. The lesion typically arises in the metaphysis of long bones and may migrate toward the diaphysis with growth. There have never been reports of nonossifying fibroma involving epiphysis that we know of. We report a very rare case of nonossifying fibroma involving metaphysis and epiphysis in a young adult. Written, informed consent was obtained from the patient to publish this case report, including the images.