|
|
|
« Back
Rare But Serious Bone Tumor in Children
|
Posted on: 10/23/2008
|
Lumps in soft tissue or over bone always raise the suspicion of a tumor. But some slow-growing tumors may be unseen for several years before discovery. This can cause significant delays in diagnosis and treatment.
That's what happened in this case of a 13-year-old boy with right knee pain. At first, the pain was mild, but didn't limit function or sports participation. But overtime, the pain increased until the child was no longer able to walk long distances or run.
When he went to see a pediatric orthopedic surgeon, there was no swelling, redness, or inflammation of the joint or surrounding soft tissues. He had full motion of the ankle, knee, and hip. The physical exam was essentially normal.
A diagnosis of proximal tibial epiphyseal intraosseous schwannoma was made with the help of advanced imaging studies (X-rays, CT scans, MRIs). Proximal means the problem was located near the top of the tibia (lower leg bone). Epiphyseal refers to the growth plate at the end of the bone. And intraosseous means the schwannoma (tumor) was in the bone.
The fact that the tumor turned out to be a schwannoma was significant because schwannomas (also known as neurilemmona) usually occurs in the lining of nerve tissue (not bone). This is the first report of such a problem in a child. So, it's understandable that a diagnosis of the problem was delayed by several years.
The diagnosis was confirmed by doing an excisional biopsy (removal of the tumor). The tissue was sent to a lab for analysis. They found a soft, yellow, myxoid (mucous-like) tissue mixed with bone. The biopsy was the treatment. Once the tumor was removed, the hole was filled with a combined bone graft and bone substitute. Successful results were reported. The patient was pain free with full motion after one month. He was able to go back to full sports participation. Follow-up showed no recurrence of the condition.
The authors make note of the fact that a diagnosis of intraosseous schwannoma/neurilemmoma was never considered during the workup. Tumors of the nerve sheath are rare and even more so in children.
Doctors aren't sure how a schwannoma of bone occurs. There are several possible explanations. First, tiny nerve fibers from each spinal nerve are known to enter the bone. These nerve filaments also have their own blood supply. Once the tumor gets started, blood from the nerve filaments is diverted to the tumor.
The tumor cells may originate in the bone marrow where schwannoma cells are found. Or it could come from the nutrient vessel supplying blood to the bone. Sometimes, the tumor comes from the nerve tissue that erodes (eats) into the bone.
The authors point out that schwannomas affecting the growth area of the bone in children are very rare. But as this report shows, they can occur in children and should be part of the list of possible diagnoses.
To help identify intraosseous schwannomas, the authors provided a description of one other similar bone tumor. They compared a typical schwannoma with a chondroblastoma. This may help surgeons consider other potential causes of joint pain when making the diagnosis.
X-rays of a benign chondroblastoma look much like X-rays of this child. And the child's signs and symptoms were pretty much the same as they would be with a chondroblastoma. Even the location was the same for the most common chondroblastomas (proximal tibia). There were some differences in the signal intensity of the MRIs between an intraosseous schwannoma and a chondroblastoma. But the main difference was the pathology report of the tumor.
The authors conclude that even though intraosseous schwannomas are rare, surgeons should be aware that this could be the potential diagnosis. This case report confirms the need to depend on the pathologist's report before settling on one diagnosis over another.
|
References:
Alain Meyer, MD, et al. Proximal Tibial Epiphyseal Intraosseous Schwannoma. A Rare Entity. In Journal of Pediatric Orthopaedics. October 2008. Vol. 28. No. 7. Pp. 786-790.
|
|
|
« Back
|
|
|
|
*Disclaimer:*The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic. |
 | All content provided by eORTHOPOD® is a registered trademark of Mosaic Medical Group, L.L.C.. Content is the sole property of Mosaic Medical Group, LLC and used herein by permission. |
|
