An enchondroma is a type of non-cancerous bone tumour that originates from cartilage, the specialised, gristly connective tissue from which most bones develop. The bones most often involved are the miniature long bones of the hands and feet, though the condition may also involve other bones such as the femur, humerus, or tibia.

While it may affect an individual at any age, it is most common in adulthood, and occurrence between males and females is equal. 

An enchondroma may occur as an individual or several tumours. The conditions that involve multiple lesions include the following:

Ollier disease

Also known as enchondromatosis, this frequently occurs in the small bones in the hands and toes (phalanges) and the long bones behind the phalanges, called metatarsals. 

Maffucci's Syndrome

This is a very rare condition that combines multiple enchondromas in bones anywhere in the body with benign soft tissue tumours (known as hemangiomas), which are associated with blood vessels. Maffucci’s Syndrome tends to appear in the hands and feet, and has a greater tendency toward malignant transformation than Ollier's Disease.

Because they are painless, most enchondromas are only discovered when X-rays are taken for another reason. The majority of enchondromas require no treatment, though they can be aggressive and require further attention – usually in the form of surgery.