151. Sciatic nerve tumour visualizable with ultrasound even in proximal districts.

High-resolution ultrasound (US) is a helpful technique for the evaluation of peripheral nerves and literature data show that US may crucially influence diagnosis and clinical care in entrapment in nerve tumours. We report the case of a 48year-old woman complaining of pain and electric shocks radiated in sciatic course and trigger point in the gluteal region. It was suspected radiculopathy due to disk herniation. MRI showed mild L5–S1 bulging. Due to the trigger, US of sciatic nerve was suggested, nevertheless the trigger was in a region where usually sciatic nerve is not depictable (commonly accepted that is not depictable proximally to plica glutea). The clinical examination and EMG were normal. We performed an ultrasound examination to study sciatic nerve from its distal formation by the union of peroneal and tibial nerves and along its proximal tract. The right sciatic nerve was visualizable along all its tract, even proximally to plica glutea. At the middle-third of gluteus the nerve showed a round-oval shape formation with homogeneous hypoechoic US image. After accurate evaluation the formation seemed on the nerve edge and nerve fibers seemed dislocated laterally, moreover the proximal edge was clearly visualizable. The morphology suggested a probable neurinoma. MRI confirmed dislocation of fascicles and surgical excision was planned. This case report shows the importance of trying ultrasound sciatic nerve examination even proximal to plica glutea. [Copyright &y& Elsevier]