A nonossifying fibroma is a non-malignant tumor that occurs in adolescents and children. The fibroma is always found near the end of the long bones, usually those in the legs. Though a fibroma causes little to no pain, large fibromas increase the chance of bone fracture, especially if the adolescent participates in a physical activity such as sports. Only large fibromas that cause intense pain or fracture need to be removed through surgery. In most cases, though, a fibroma will disappear as the adolescent continues to grow.
It is not yet clear why some adolescents develop this condition. One theory is that while a child is developing in the womb, blood flow within the long bones is misdirected. Though other theories try to explain the root cause, the medical community agrees that the condition is caused by a developmental defect. As a nonossifying fibroma takes time to develop, it is not possible to test for the condition immediately after birth.
Symptoms of a nonossifying fibroma are rare or nonexistent. Most adolescents who have a fibroma never know it, though in some cases an adolescent may complain of an aching feeling in a joint. With a large fibroma, the most common symptom is bone fracture during a physical activity. A post-fracture x-ray can confirm the presence of this kind of fibroma.
Treating a nonossifying fibroma depends on both the adolescent's present health and the nature of the fibroma. If the fibroma is small and causes little discomfort, a doctor may decide to do nothing and let the adolescent grow out of it. Surgery is necessary, though, when a fibroma causes significant discomfort, structural weakening of the bone, or fracture.
Surgery consists of both curettage and bone grafting. A surgeon will remove the fibroma, creating a gap in the bone. Pieces of donor bone are inserted into the gap. During the six-week period when the leg is in a cast, donor bone fuses with the adolescent's natural bone. In six months, the adolescent will be fully able to participate in all physical activities.
Prognosis for the future is excellent even in cases when an adolescent undergoes surgery. Unlike malignant tumors, there is very little chance that a nonossifying fibroma will reappear. Though parents of adolescents who have undergone corrective surgery may want to have their child checked for other fibromas, the chances of having two or more large fibromas is statistically insignificant and only occurs in rare conditions that have other prominent symptoms.