Chronic spinal syndromes without evidence of cord compression often represent a real diagnostic challenge. We report a case of chronic progressive myelopathy with an unusual long-standing gadolinium-diethylenetriamine pentaacetic acid (Magnevist, Berlex Laboratories) enhanced spinal cord lesion demonstrated on MRI, through a 14 month follow-up period. In the context of continuous neurological decline the patient underwent two biopsies at 1 year intervals. The final diagnosis was obtained only after the second biopsy, which demonstrated a demyelinating plaque with reactive astrocytosis. The clinical condition of our patient has been stable for 5 years. A repeated workup including MRI of the cervical and thoracic spine demonstrated a mildly atrophic cord in the upper thoracic region, with no evidence of pathological signal or enhancement at this time. Brain MRI and visual evoked potentials were normal. This case provides interesting clinical, pathological, and MRI correlations in a longitudinal follow-up of a spinal demyelinating lesion.