A case of subacute progressive spinal tetraparesis had myelographic evidence of cervical spinal cord swelling and a delayed metrizamide computed tomographic myelogram (MCTM) suggested cavitation within the swollen spinal cord. Surgical exploration of the cervical cord revealed inflammatory changes only. No syrinx or intramedullary tumour was found. The accumulation of metrizamide within the spinal cord, as demonstrated by MCTM, did not’respresent a syrinx or a cystic tumour, but more likely an area of inflammation. Because inflammatory myelopathy may simulate an intramedullary tumor or syrinx, careful analysis of all clinical and radiological information is necessary to help make a correct diagnosis.