Non-ossifying fibroma

{{short description|Benign bone tumor type}}

{{Infobox medical condition (new)

| name = Non-ossifying fibroma

| synonyms = Fibroxanthoma

| image = NOF 1.jpg

| caption = X-ray of nonossifying fibroma of distal tibia.

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A non-ossifying fibroma (NOF) is a benign bone tumor of the osteoclastic, giant cell-rich tumor type.{{cite book|title=Soft Tissue and Bone Tumours: WHO Classification of Tumours|url=https://books.google.com/books?id=kaR9zQEACAAJ|year=2020|editor=WHO Classification of Tumours Editorial Board|publisher=International Agency for Research on Cancer|location=Lyon (France)|edition=5th|volume=3|isbn=978-92-832-4503-2|chapter=Non-ossifying fibroma|

pages=447–448}} It generally occurs in the metaphysis of long bones in children and adolescents.{{cite book|last1=Murali|first1=Sundaram|url=https://books.google.com/books?id=qGmnCQAAQBAJ|title=Tumors and Tumor-Like Lesions of Bone: For Surgical Pathologists, Orthopedic Surgeons and Radiologists|last2=Ilaslan|first2=Hakan|last3=Holden|first3=Darlene M.|date=2015|publisher=Springer|isbn=978-1-4471-6577-4|editor-last=Santini-Araujo|editor-first=Eduardo|page=15|language=en|chapter=2. An imaging approach to bone tumors|quote=|editor-last2=Kalil|editor-first2=Ricardo K.|editor-last3=Bertoni|editor-first3=Franco|editor-last4=Park|editor-first4=Yong-Koo}} Typically, there are no symptoms unless there is a fracture. 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, intellectual disabilities, hypogonadism, eye and cardiovascular abnormalities.

Diagnosis is by X-ray or MRI, usually when investigating a person for something else. Medical imaging typically shows a well defined radiolucent lesion, with a distinct multilocular appearance, sometimes looking like bubbles. It is usually around 1–2 cm in size, but be as large as 7 cm.{{cite book |last1=Paulos |first1=Jaime |title=Bone Tumors: Diagnosis and Therapy Today |date=2021 |publisher=Springer |isbn=978-1-4471-7501-8 |pages=139 |url=https://link.springer.com/chapter/10.1007/978-1-4471-7501-8_22 |language=en |chapter=Non Ossifying Fibroma|doi=10.1007/978-1-4471-7501-8_22 |s2cid=238034517 }} They consist of foci consist of collagen rich connective tissue, fibroblasts, histiocytes and osteoclasts. Usually no treatment is required. Surgical curettage and bone grafting may be required if it is large.

It is found in 30–40% of children and adolescents, but rare in adults as most have resolved by this time. They do not become malignant. It affects twice as many males as females. A NOF was identified on the mandible of Qafzeh 9, an early anatomically modern human dated to 90–100 000 yrs B.P.Coutinho Nogueira D, Dutour O, Coqueugniot H, Tillier A.-m., (2019) Qafzeh 9 mandible (ca 90–100 kyrs BP, Israel) revisited : μ-CT and 3D reveal new pathological conditions, International Journal of Paleopathology, Vol 26, pp.104-110, https://doi.org/10.1016/j.ijpp.2019.06.002