Primary schwannoma of the bone: a clinicopathologic and radiologic study of 17 cases

Primary schwannoma of the bone, defined as arising within the medullary cavity and radiologically mimicking more common primary bone tumors, is rare. We present 17 tumors, 13 conventional schwannomas, and 4 melanotic type. Collectively, they represented <1% of all primary bone tumors seen at Mayo Clinic over a 33-year period. Most tumors affected long bones. There was a slight female predilection. Fifteen tumors were sporadic, and 2 were syndrome associated (Carney complex). Pain was the most common symptom. Given their rarity, schwannomas of the bone are not usually included in the differential diagnosis of primary osseous spindle cell tumors. Thus, they are prone to misdiagnosis and overtreatment. Similar to their more common extraosseous counterparts, primary schwannomas of the bone behave in a benign manner and are successfully treated by local excision alone.