A chondroma is a cartilage-producing tumor. It is usually benign, meaning it doesn’t spread to other parts of the body. It is not likely to cause death. Most of these tumors occur in the tubular bones of the fingers and toes.
Extraosseous means outside the bone. Chondromas don’t usually invade the soft tissues around the bone, but they can. When this happens, the type of chondroma is a chondroma of soft parts. This type of chondroma can affect the nail bed, synovium (joint lining), or other areas around the joint.
Some extraosseous chondromas occur right next to the bone. These are referred to as juxtacortical chondromas. Regardless of where these tumors develop, they usually cause pain, local swelling, and an obvious mass (bump under the skin). They are slow-growing and may be present for years before becoming bothersome enough to see a doctor.
Any adult of any age can be affected. There doesn’t appear to be any difference in the number of men affected versus women. Juxtacortical chondromas tend to develop in younger adults between the ages of 18 and 26, but again, anyone of any age can develop this type of chondroma.