1, under the nail bone warts also called exogenous bone warts (solitary osteochondroma), is one of the common clinical bone tumors. 2, the clinical performance of the nail bone warts nail bone warts most of the single, good occurrence foot bunion, common in young people under 20 years old. The growth is similar to the bone, often from the toenail under the occurrence, performance for toenail deformity, so called: under the nail bone warts. The actual pain is often not conscious symptoms, because gradually growing hard mass, resulting in toenail deformity or discomfort is its clinical characteristics. 3, under the nail bone warts diagnosis based on the medical history, age, clinical performance, the good parts, X-ray examination, more can be clearly diagnosed. The exact cause of the disease is still unclear. Some people believe that osteochondroma is a real tumor; others believe that it is a lack of developmental epiphyseal growth. The difference between subxiphoid osteochondroma and osteochondroma is that osteochondroma can stop growing with age, while subxiphoid osteochondroma does not stop growing with age. 4, the prognosis: surgical excision effect is good, surgical excision of the bottom is generally not recurring. The actual fact is that you can find a lot of people who are not able to get a good deal on this kind of things.