Imaging Features of Intramedullary Spinal Cord Lesions with Histopathological Correlation

Abstract

Purpose Most of the intramedullary spinal cord lesions have a component of insidious myelopathic changes at the time of diagnosis. Among the spinal cord lesions, intramedullary neoplasms are rare (25%). They represent 4 to 10% of all central nervous system tumors. But due to involvement of tracts, they are associated with significant neurological symptoms. Their imaging features can help early diagnosis and predict prognosis. We aim to narrow down differential diagnoses of intramedullary lesions based on imaging findings. Materials and Methods This retrospective study included 40 patients as a sample that underwent magnetic resonance imaging spine at our institution (on 3T machine). Patient population had varied clinical complaints, ranging from headache, nausea, vomiting, motor weakness, bladder and bowel involvement, progressive paraparesis to paraplegia. Lesions were evaluated site, size, margin, associated cysts, signal intensity, enhancement, and associated syringohydromyelia. Results This study obtained majority of the lesions to be ependymoma (15) and astrocytoma (11), followed by infection (4), hemangioblastoma (3), and metastasis (2). Five patients were either lost to follow-up or not operated on. Conclusion Most of the intramedullary lesions were malignant and were showing postcontrast enhancement. Ependymomas were more frequently present in cervical region, central in location with well-defined margins and focal postcontrast enhancement. Among the total of 15 ependymomas, three cases were associated with neurofibromatosis-2. Ependymomas were more frequently associated with syringohydromyelia and peripheral hemorrhage (cap sign). Astrocytoma was more frequently seen in children, thoracic and eccentric in location with ill-defined margins. Enhancement in astrocytoma was dependent on the grade of tumor. Metastasis was a differential, with imaging characteristics dependent on type of primary. Intramedullary granuloma due to infection can also be confusing mimics of neoplasm. High-velocity signal loss due to flow voids is seen in the hemangioblastomas.