What Is Hereditary Multiple Exostoses?

Hereditary Multiple Exostoses (HME), also known as Multiple Osteochondromatosis or Multiple Hereditary Exostoses (MHE), is a genetic disorder that affects bone growth. Benign tumors, also known as exostoses, form on the growth centers of bones. The size, location, and number of tumors will vary from person to person.

Most cases of Hereditary Multiple Exostoses involve the formation of many tumors, mainly during childhood and early adolescence. The tumors can grow on any bone but are most commonly found on long bones, shoulder blades, and the pelvis. Although HME is a hereditary condition passed through genes from an afflicted parent, growths are not usually found at birth. The growths usually appear before the child reaches 12 years old.

Tumors are found near the ends of bones, at the growth centers. Their location leads to poor bone growth. A child’s growth is, therefore, stunted. In many instances, these tumors continue to grow as the child grows, but stop appearing once the person reaches adulthood and the bones stop growing.

Patients often find Hereditary Multiple Exostoses both bothersome and painful. Growths on joints can be painful when accidentally bumped. Arms and legs can bow inward, which can be uncomfortable. Stiffness is common as well. In some cases, nerves and tendons can be compressed, which affects movement and often necessitates surgical repair to avoid damage.

Many instances of Hereditary Multiple Exostoses do not require major treatment. For cases that cause problems, surgical removal is the common option. In patients who do not have immediate mobility issues, physical therapy can help patients learn how to compensate for the differences in the range of motion.

Regular monitoring by a specialist is necessary. Doctors must be able to closely watch children as they grow, particularly monitoring any new growths and their locations. If a doctor sees a growth may be causing a problem or has the potential to be problematic, it can be removed beforehand.

Patients who experience pain and stiffness can benefit from pain management. Pain from Hereditary Multiple Exostoses can generally be managed with alternating hot and cold therapy. Sometimes, however, pain medications are necessary.

Careful monitoring of Hereditary Multiple Exostoses is also necessary to ensure that the non-cancerous growths do not become malignant. Rare cases have occurred when a benign growth becomes a chondrosarcoma. At this point, removal and cancer treatment are needed. Most cases that have become cancerous have occurred in adults who have not had any new growths.