Ultrasonographic Features of Schwannoma of the Lower Limb: Two Case Reports

Schwannoma is a benign encapsulated nerve sheath tumor. It typically develops in middle age with unknown cause and usually involves spinal root and peripheral nerves. We report two cases of schwannoma presenting as palpable mass over lower limbs. Both masses had heterogeneous hypoechogenicity, faint posterior enhancement , and were located eccentric to a nerve fascicle. Preoperative sonography revealed both patients had nerve tumors derived from nerve fascicles. These cases illustrate how sonographic information about the relationship between mass and surrounding structures can facilitate surgical planning. ( Tw J Phys Med Rehabil 2008; 36(3): 169 – 175 )