We report 2 patients presenting with signs and symptoms of a medullary lesion. Spinal magnetic resonance imaging (MRI) using surface coils showed a volume increase of the spinal cord. Multiple sclerosis (MS) was suspected on the clinical evolution, the cerebrospinal fluid oligoclonal pattern in one case and the return of the cervical cord to an almost normal calibre on successive MRI. This diagnosis was further supported by the results of encephalic MRI. Such a pseudotumoral aspect of the spinal cord in MS has rarely been reported, and probably has been underestimated. MS should be considered in the differential diagnosis of localised enlargement of the spinal cord.