[Synovial lumbar cyst].

The Authors report a case of low back pain with sciatica due to a synovial cyst of the interapophyseal joint of the lumbar spine. The diagnosis was made by CT and MRI. A review of the literature confirms the relative rarity of their lesion at the lumbar level and the necessity of radical surgery, best achieved with microsurgical technique. The Authors emphasize the importance of accurate diagnosis before surgery.