We report a case of 66 years-old male with left leg pain that began six months earlier. The pain was aggravated by sitting or climbing stairs but was relieved in the standing position. The physical examination was consistent with a left radiculopathy without sensory or motor deficit. His initial MRI lumbar spine demonstrated a cystic mass with T1 and T2 hyperintensity on the L3-L4 level with considerable thecal sac and nerve root compression. The lesion originated next to the left L3-4 facet joint and extended centrally under the lamina of L3 and L4. A surgical treatment was offered to the patient and subsequently underwent a left L3 hemilaminectomy, medial facetectomy, left ganglion excision and L3, L4 fusion, with a very satisfactory outcome.Spine ganglions are grouped within yuxta-articular facet cysts, along with synovial cysts. Etiology is unknown, but it is related with repeated trauma or microtrauma as a part of degenerative spinal disease. It is an uncommon pathology and 90% are located in the lumbar region. The most common symptom is pain and the radiculopathy, which is unusual; it will be due to compression of adjacent structures. Initial treatment is conservative. Surgery is indicated in cases where a neurological deficit exists or where conservative treatment fails in pain relief. Generally good results are described. In our case the patient had a very satisfactory outcome.

Its superior resolution of tissue and spatial contrast make it more specific and sensitive in the evaluation of soft tissues as well as in the infiltrative disorders of the bone marrow, metastasis, infections or reactive changes of the saucer.The disadvantages of MRI are relatively few. It is considered that its cost is approximately double that of