A 40-year-old male presented with a 3-year history of sensory changes involving the S2–S3 distribution in the right leg (e.g., hypoesthesia without motor weakness or dysuria). The lumbosacral MRI showed a noncontrast enhancing right-sided cystic mass at the S2–S3 level; it had the same intensity as CSF on both the T1- and T2-weighted images []. Coronal fat-suppressed T2-weighted images revealed the mass likely originated from the right S3 nerve root and was additionally compressing the right S2 nerve root [].\nA laminoplastic laminotomy was performed at three levels using an ultrasonic bone curette. At surgery, the S3 nerve root was enveloped within cyst wall and the S2 nerve root was clearly compressed [Figure and ]. Partial resection of the cyst wall and imbrication of residual tissue was performed []. An inlet from the subarachnoid space was identified, and its obliteration was confirmed by a Valsalva maneuver []. This subarachnoid connection was sealed with adipose tissue and fibrin glue []. Plication of the cyst wall was performed with nonpenetrating titanium clips (Vascular Clip System; LeMaitre Vascular Inc., Burlington, MA) []. No postoperative CSF leakage occurred, and spinal lumbar drainage was not warranted. The patient's preoperative sensory disturbance resolved. The postoperative MRI showed a reduction in the cyst's size [Figure and ] and no residual compression of the S2 nerve root []. Histopathological examination confirmed collagen connective tissue without nerve fibers, findings consistent with a Tarlov cyst []. The patient remained asymptomatic 6 months later, and the 6-month postoperative sacral MRI demonstrated no cyst recurrence.
This 21-year-old man complained of worsening radiating pain and hypesthesia on left leg for 1 year. His motor weakness was grade 4 on left leg, especially when extending the left ankle. Because of worsening symptoms he eventually visited our department. He had mild claudication, positive on left straight leg raising test at 45 degree. We confirmed a mild left S1 radiculopathy on electromyography. He had no neurologic deficit associated with cauda equina syndrome. Preoperative MR imaging showed a 20×13×14 mm sized sacral cyst (). We performed myelogram and CT and found the contrast-filled stalk between the thecal sac and the cyst. The cyst compressed a contiguous structure including nerve roots ().\nWe performed surgery the same as patient 1 () and symptoms disappeared after one week. Follow up MR imaging after 2 months demonstrated complete resolution of the lesion. We checked with MR imaging after 1 year and ascertained that there was no further cystic formation and complication ().