Chordomas and Their Consideration in the Radiographic Differential of Extra-Axial Lesions of the Central Nervous

Due to the rare occurrence of chordomas extra-axially, these lesions have not earned a great deal of consideration in the clinical and radiographic differential diagnoses of extra-axial paraspinal lesions. We describe a case of a patient with a surgically resected extra-axial chordoma and review the radiologic characteristics of chordomas as an entity in the spectrum of extra-axial lesions. A 47-year-old man presented to our institution with four months of intermittent parethesias, pain, and subjective weakness in the left leg. MR imaging of the lumbar spine demonstrated a large heterogeneouslyenhancing paraspinal lesion extending from the left L3-4 neural foramen into the psoas muscle. The patient underwent a CT-guided needle biopsy demonstrating features consistent with a chordoma. He then underwent a left retroperitoneal approach and en bloc resection of the lesion from the vertebral column. Pathology confirmed chordoma as the diagnosis. EACs are a rare but important consideration in the diagnosis of extra-axial lesions of the central nervous system.