Prevalence of spinal meningeal cyst in the sacrum.

Spinal meningeal cysts in the sacrum (SMC) are known to be occasionally symptomatic with low back pain as well as leg pain, but no distinct prevalence of this pathological entity including asymptomatic lesions has been described. This prospective study investigated the prevalence of SMCs based on magnetic resonance (MR) myelography in 102 consecutive Japanese women with gynecological problems, who underwent pelvic conventional MR imaging. Ten of 102 patients were suspected of being positive for SMC (9.8%), but pseudo-positive findings were possible. A high probability of positive SMC was found in 7/102 (6.9%). MR myelography was better to detect SMCs than conventional MR imaging. Multiplicity and female preponderance may be other features of SMC. The speculated prevalence of SMCs in Japanese females ranged from 6.9% to 9.8%.