Clinical experience of symptomatic sacral perineural cyst.

Tarlov or perineural cysts are nerve root cysts found most commonly at the sacral spine level arising between covering layers of the perineurium and the endoneurium near the dorsal root ganglion and are usually asymptomatic. Symptomatic sacral perineural cysts are uncommon but sometimes require surgical treatment. A 69-year-old male presented with pain in the buttock. He was diagnosed as having a sacral cyst with magnetic resonance imaging. For the nonoperative diagnosis and treatment, caudal peridurography and block were performed. After the treatment, the patient's symptom was relieved. We suggest a caudal peridural block is effective in relieving pain from a sacral cyst.