| Non-ossifying fibroma | |
| Synonyms: | Fibroxanthoma |
A non-ossifying fibroma (NOF) is a benign bone tumor of the osteoclastic giant cell-rich tumor type.[1] It generally occurs in the metaphysis of long bones in children and adolescents.[2] Typically, there are no symptoms unless there is a fracture.[2] It can occur as part of a syndrome such as when multiple non-ossifying fibromas occur in neurofibromatosis, or Jaffe–Campanacci syndrome in combination with cafe-au-lait spots, mental retardation, hypogonadism, eye and cardiovascular abnormalities.[2]
Diagnosis is by X-ray or MRI, usually when investigating a person for something else.[2] Medical imaging typically shows a well defined radiolucent lesion, with a distinct multilocular appearance, sometimes looking like bubbles.[2] It is usually around 1–2 cm in size, but be as large as 7 cm.[3] They consist of foci consist of collagen rich connective tissue, fibroblasts, histiocytes and osteoclasts.[2] Usually no treatment is required.[1] Surgical curettage and bone grafting may be required if it is large.[3]
It is found in 30–40% of children and adolescents, but rare in adults as most have resolved by this time.[2] They do not become malignant.[2] It affects twice as many males as females.[2] A NOF was identified on the mandible of Qafzeh 9, an early anatomically modern human dated to 90–100 000 yrs B.P.[4]
Most people with non-ossifying fibroma have no symptoms.[1] If the tumor is large, there may be pain over the affected area, a pathological fracture, and the affected limb might not function properly.[1] It can occur as part of a syndrome such as when multiple non-ossifying fibromas occur in neurofibromatosis, or Jaffe–Campanacci syndrome in combination with cafe-au-lait spots, mental retardation, hypogonadism, eye and cardiovascular abnormalities.[2]
It is usually diagnosed by x-ray or MRI, when investigating another problem.[1] The tumor presents as a well defined radiolucent lesion, with a distinct multilocular appearance, sometimes looking like a "soap bubble".[5] If small and no symptoms, then biopsy is not needed.[1]