case_images: PMC6130174_01
case_images: Lumbosacral magnetic resonance images. Sagittal (a and b), axial (c), and coronal (d) view of lumbosacral magnetic resonance imaging showing the cyst (red arrow) at the S2 vertebra. Preoperative magnetic resonance images showing a less-enhanced tumor (b). The contents of the cyst have the same intensity as the cerebrospinal fluid on both T2-weighted images
case_images: SNI-9-180-g001.jpg
case_images: PMC6130174_01_SNI-9-180-g001.jpg
case_images: F1
case_images: CSF on both the T1- and T2-weighted images [Figure 1]. 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 [Figure 2].
case_images: The relationship between the cyst and the nerve roots. (a) Coronal fat-suppressed T2-weighted imaging shows that the cyst (asterisk) likely originated from the right S3 nerve root. (b) The cyst compresses the right S2 nerve root
case_images: SNI-9-180-g002.jpg
case_images: PMC6130174_01_SNI-9-180-g002.jpg
case_images: F2
case_images: CSF on both the T1- and T2-weighted images [Figure 1]. 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 [Figure 2].
case_images: Operative procedure and intraoperative findings. (a) Intraoperative photograph showing that the S2 nerve root (double arrowheads) was compressed by the cyst component (white asterisk). (b) Closer observation revealed that the cyst wall (white asterisk) contains the S3 nerve root (double arrows). (c and d) After excision of the cyst wall, the inlet of the cerebrospinal fluid (CSF) was confirmed around the nerve root (single arrow). The inlet from the subarachnoid space was found (single arrowhead) and the CSF was spontaneously flowing out from it (small triple arrows). A Valsalva maneuver clearly showed the CSF flow from the subarachnoid space to the perineural cyst. (e) After confirmation of the subarachnoid connection, it was sealed with adipose tissue (large arrow) and fibrin glue. (f) Finally, imbrication of the cyst wall was performed with nonpenetrating titanium clips. A repeated Valsalva maneuver showed no CSF leakage
case_images: SNI-9-180-g003.jpg
case_images: PMC6130174_01_SNI-9-180-g003.jpg
case_images: F3
case_images: At surgery, the S3 nerve root was enveloped within cyst wall and the S2 nerve root was clearly compressed [Figure 3a and b]. Partial resection of the cyst wall and imbrication of residual tissue was performed [Figure 3c]. An inlet from the subarachnoid space was identified, and its obliteration was confirmed by a Valsalva maneuver [Figure 3d]. This subarachnoid connection was sealed with adipose tissue and fibrin glue [Figure 3e]. Plication of the cyst wall was performed with nonpenetrating titanium clips (Vascular Clip System; LeMaitre Vascular Inc., Burlington, MA) [Figure 3f].
case_images: Postoperative magnetic resonance imaging. Postoperative magnetic resonance imaging showed a reduction in cyst (red arrow) size (a and b). There was no compression of the S2 nerve root (c)
case_images: SNI-9-180-g004.jpg
case_images: PMC6130174_01_SNI-9-180-g004.jpg
case_images: F4
case_images: The postoperative MRI showed a reduction in the cyst's size [Figure 4a and b] and no residual compression of the S2 nerve root [Figure 4c].
case_images: Histopathological examination of the cyst. (a and b) Histopathological specimen from the cyst wall. The histopathological examination indicated that the wall was composed of collagen connective tissue without nerve fibers (H and E staining)
case_images: SNI-9-180-g005.jpg
case_images: PMC6130174_01_SNI-9-180-g005.jpg
case_images: F5
case_images: Tarlov cyst [Figure 5]. The patient remained asymptomatic 6 months later, and the 6-month postoperative sacral MRI demonstrated no cyst recurrence.