Our nine-year-old son was injured playing baseball, which turned out to be a good thing because when they X-rayed his arm for fractures, they found a tumor the size of a golf ball. They think it is a lipoma (fat tumor). We had no idea. He hasn’t had any pain and there’s nothing on the outside more than a slight bump to suggest a problem. We are waiting to see the orthopedic surgeon about this. What can you tell us while we wait?

Tumors of the arms and legs in children are actually fairly common. Fortunately, they are also usually benign. A careful and accurate diagnosis is still important as your orthopedic surgeon will probably tell you.

The physician making the diagnosis in these cases must be very thorough as many cases can be extremely challenging. Diagnostic information must be gathered from multiple sources including the clinical presentation, imaging, and tissue biopsy and cell histology. This level of detailed diagnostic information also guides non-surgical management as well as treatment with all other modalities (radiation, chemotherapy, surgery).

Treatment principles of soft tissue masses in children depend on several factors. These include the type of tumor (benign versus malignant, slow versus fast growing), symptoms, and age of the child. For example, small, benign tumors that are not causing any symptoms or problems may be watched and monitored without doing anything. Most benign but symptomatic tumors are removed surgically.

Lipoma is a relatively uncommon benign tumor in children and involves the overproduction of fat cells. Benign means nonmetastasizing (does not spread to other parts of the body) but local growth can put pressure on other tissues creating other problems. And tumors can become large enough to present cosmetic problems. Every effort is made to provide treatment that leaves the extremity intact and as normal appearing as possible. Even with surgical excision (removal), these tumors can grow back requiring additional surgery to remove them when necessary.