Bronchogenic cyst of the conus medullaris with spinal cord tethering: a case report and review of the literature.

Bronchogenic cysts (BCs) are congenital malformations that originate from remnants of the primitive foregut. Intraspinal BCs, especially those of the conus medullaris are rare with only one case reported until now. To date, a bronchogenic cyst with spinal cord tethering has not been previously reported. We reviewed the clinical course of a 44-year-old woman, who presented with low back pain and leg weakness as well as sphincter disturbance. Magnetic resonance imaging showed an intradural oval mass located at the conus medullaris. A tethered cord was also observed, as well as a dermal sinus tract. The mass was totally removed after an L3-L4 laminectomy without detethering during operation. Pathologic examination confirmed the diagnosis of bronchogenic cyst. By six months after treatment, the patient had experienced nearly complete recovery. The review of literature indicated that detethering was performed in most reported cases of neurenteric cysts with spinal cord tethering, and one of six patients was diagnosed with a postoperative recurrence. The co-existence of bronchogenic cyst and a tethered spinal cord would imply associated developmental errors in embryogenesis. It is worth noting that whether detethering is necessary after the cyst removal.