I’ve had a bone problem called multiple hereditary exostoses since I was a kid. It’s never bothered me and I’ve given it almost no thought. But recently, I found out that one of these bony bumps is becoming cancerous. I’m scheduled to have surgery to remove it but I’d like to know how serious is this condition?

Multiple hereditary exostoses describes a bone condition that is inherited. Something goes wrong in the gene that controls bone growth so that the cells don’t line up in well-ordered stacks like they are supposed to. Instead, they form uneven, irregular outgrowths of bone. These bony outgrowths called exostoses or osteochondromas are usually covered with a cap made of cartilage.

The condition is almost always benign in the sense that it won’t spread or cause a life-threatening situation. The changes in the bone can lead to deformities, dislocations, and limb-length differences. But occasionally, the bony bump transforms and becomes a relatively slow-growing malignant neoplasm. The areas affected most often include the pelvis, shoulder, femur, humerus, and ribs.

Pain is the most common presenting complaint, although this is a slow-growing tumor, so in some cases the tumor can exist for years without symptoms. The majority of chondrosarcomas are grade I or II, which rarely metastasize. The lesion can range from a slow-growing lesion to an aggressive malignancy capable of metastasizing to other organs.

Removing the tumors is the most efficient and effective way to treat this problem. Early removal before metastasis occurs prevents future problems.