[Three cases of surgical treatment of dumbbell neurogenic tumor of the mediastinum--evaluation of intraspinal extension in cases without clinical symptoms].

Three cases of dumbbell neurogenic tumor of the posterior mediastinum are reported. None of these cases had any clinical symptoms, and an abnormal mass shadow of the mediastinum had been detected on routine chest roentgenogram. In these three cases, however, myelogram and/or CT findings were suggestive of tumor extension to the spinal canal in various degrees. Two tumors were resected in two-stage operations with combined thoracic and neurosurgical approaches, and the other case was treated by one-stage operation with the combined two approaches. All tumors were completely resectable without serious complications such as hemorrhage, leakage of spinal fluid, or neurologic deficit. Even in asymptomatic patients with neurogenic tumor located in the paravertebral region, it should be determined whether or not the tumor extends to the spinal canal through the intervertebral foramen, prior to planning the surgical procedure.