[A case of sacral meningeal cyst with Marfan syndrome].

A rare case of sacral meningeal cyst Marfan syndrome is reported. A 40-year-old male who had a past history of Marfan syndrome was admitted to Tokyo Metropolitan Ebara Hospital due to sensory disturbance in the right S1-2 nerve root area on October 1998. On admission, neurological deficits were sensory disturbance and decrease right Achilles reflex. Plain sacral X-ray was normal. Magnetic resonance imaging revealed a cystic mass in the intrasacral space. MR myelography showed the cyst followed the thecal sac. Signal intensity of the cystic mass was the same as the cerebrospinal fluid. In the prone position, laminectomy of the sacrum was carried out. The neck of the meningeal cyst was ligated with the help of an aneurysmal needle. The patient's sensory disturbance disappeared postoperatively. As MRI becomes more frequently used in Marfan syndrome, it is important to keep the presence of such an entity in mind. MR myelography made it easy to diagnose the meningeal cyst.