Osteochondromas are benign bone tumors that form in the bone beneath the toenail. Osteochrondromas account for about half of all benign bone tumors, and occur mostly in children and young adults. Unless they cause irritation to the surrounding tissue, they are generally not painful.
In some cases, osteochondromas may cause a deformity in the toenail or lead to an ingrown toenail. When problematic, osteochondromas may be removed surgically. However, they can recur after the procedure.