Differentiation of tumor from syringohydromyelia: intraoperative neurosonography of the spinal cord.

Real-time ultrasonography was useful in differentiating tumor from syringohydromyelia as the cause of cervical cord widening in four patients. Those with syringohydromyelia had a smooth, regular, cystic space located symmetrically in the spinal cord. Tumor appeared as an echogenic, hypoechoic, or cystic expansile lesion that both narrowed the subarachnoid space and obliterated the spinal canal. When intraoperative sonography detects cystic lesions of the spinal cord, careful search for the presence of these signs is necessary to exclude tumor. Intraoperative spinal cord ultrasonography is simple and rapid, and it provides the surgeon with valuable information not readily available previously.