Curriculum · Musculoskeletal / Orthopedic / Rheumatology
Osteochondroma
What it is
Osteochondroma is a benign bone tumor that comes from cartilage, as does chondroma; the malignant tumor of that same origin is chondrosarcoma. It is a cartilage capped bony tumour and the most common of all benign bone tumours, at about 45%, given at an age of 10 to 30 on one page and in the 2nd and 3rd decades on another, with an M:F of 1.8:1. It has 2 types: sessile, broad based, which carries an increased risk of malignant degeneration, and pedunculated, with a narrow stalk. It sits in the metaphysis of a long bone near tendon attachment sites, usually the distal femur, proximal tibia or proximal humerus, and it may be multiple in a hereditary autosomal dominant form, which carries a higher risk of malignant change.
How it is diagnosed
On x-ray it is an exostosis: a cartilage-capped bony spur on the surface of the bone, described as a mushroom on x-ray.
How it is treated
Treatment is reported two ways and both should be held in mind: typically observation, with surgical excision if it is symptomatic, in one source; and surgical resection as the management given for this diagnosis in another.