We present the case of a woman who presented with weakness of both legs due to a low grade tumor of the spinal cord. Excision of the tumor was performed and confirmed with intraoperative ultrasound. Prior to dural closure the spinal cord was found to be pushed dorsally with herniation of the cord through the dural defect. Intraoperative ultrasound showed a collection of cerebrospinal fluid in an anterior pocket giving the impression of the cord being swollen. Once cerebrospinal fluid was drained, the cord settled within the thecal space and closure of the dural defect was performed. Surgery for an intramedullary spinal cord tumor can cause a significant amount of swelling and either a duroplasty is required or the dura is left open with meticulous closure of the wound. Ultrasound is helpful to identify pathology anterior to the cord and prevents the potential complications associated with duroplasty or leaving the dura open.