Spontaneous hemorrhage in an upper lumbar synovial cyst causing subacute cauda equina syndrome.

Lumbar spine synovial cysts are becoming more frequent, and they are generally associated with degenerative lumbar spinal disease. They are common in lower lumbar lesions but rare in upper lumbar lesions. Several cases of hemorrhage into lower lumbar juxtafacet cysts after trauma or anticoagulation therapy have been reported in the literature. This article describes a case of subacute cauda equina syndrome resulting from spontaneous hemorrhage into an upper lumbar synovial cyst. A 65-year-old man presented with a 3-month history of intermittent bilateral lumbar pain. One week before, he experienced a sudden exacerbation of lumbar pain and began falling frequently; he also reported weakness and tingling in his lower limbs. A hematic collection associated with a large juxtafacet cyst at L2-L3 was suspected on magnetic resonance imaging. He underwent surgical decompression, and the cyst was resected. Microscopic examination was consistent with the diagnosis of a synovial cyst. Two days postoperatively, he was walking independently. Although several descriptions exist of hemorrhagic lumbar juxtafacet cysts after trauma or anticoagulant therapy, to the authors' knowledge, this is the first documented case of hemorrhage in an upper lumbar synovial cyst with no previous traumatic event or medication use. Magnetic resonance imaging was essential in making the preoperative diagnosis. Surgical removal of the cyst was an effective treatment.