Differential Diagnosis of Intramedullary Spinal Cord Lesions mimicking Tumors

Abstract

The diagnosis of intramedullary spinal cord lesions is occasionally difficult. It is important to distinguish tumors from nonneoplastic intramedullary lesions. The purpose of this study was to elucidate characteristics that would aid in preoperative differential diagnosis. We report on nine patients with intramedullary spinal cord lesions which were diagnosed with difficulty. Six patients were diagnosed based on clinical presentation, radiographic findings and laboratory examinations. The diagnoses were multiple sclerosis in two patients, neurosarcoidosis in two patients and spinal cord infarction in two patients. In three patients, differential diagnoses were difficult to achieve preoperatively, and biopsies were performed. In one patient, T2-weighted magnetic resonance images (MRI) showed multiple high intensity areas in the brain and the conus medullaris. Although there were few clinical features that distinguish gliomatosis cerebri from multiple sclerosis in the early stages, the signs of increased intracranial pressure such as headache and papilledema appeared afterwards. Histology of the surgical specimen from the brain lesion showed anaplastic astrocytoma. The patient showed tumor progression and died during the follow-up. Pathological examinations of the other surgical specimens from the spinal cords revealed hamartomatous dysplasia (secondary changes in vascular malformation) and glial tissue (contusion due to narrowing of the canal). Analysis of angiotensin converting enzyme (ACE) in cerebrospinal fluid was useful in the diagnosis of neurosarcoidosis. The sequential changes on MRI were of value in diagnosing ischemic cord infarction. Nevertheless we stress the importance of close follow-up evaluations of clinical symptoms. Indication of biopsy or surgical treatment should be carefully determined to avoid unnecessary cord exploration and biopsy.