case_images: PMC10481812_01
case_images: (Patient 1) (a and b) Photographs of the skin lesion, shows a dimple (blue arrows) under the groove on the right side. (c-f) Sagittal view of 3D-hT2WI (c) and axial views of T1WI (d-f). Each slice level of the axial views (d-f) is indicated by red arrows on (c). Each level of the vertebral columns from L3 to S5 is indicated on (c). The caudal cyst wall is partly composed of lipomatous tissue (d,e, yellow arrows). A stalk extending from the subcutaneous fat into the vertebral canal is shown as blue arrows [panel (f)]. 3D-hT2WI: three-dimensional heavily T2-weighted image, T1WI: T1-weighted image.
case_images: SNI-14-279-g001.jpg
case_images: PMC10481812_01_SNI-14-279-g001.jpg
case_images: F1
case_images: A Y-shaped groove continuous from the gluteal cleft was noted [Figure 1a], and a dimple was observed under the groove on the right side [Figure 1b, blue arrow]. Magnetic resonance imaging (MRI) revealed the caudal spinal cord and continuous C-LS, with a large cyst at the S1-S3 of the vertebral level, with cord tethering [Figure 1c]. The caudal cyst wall was partly composed of lipomatous tissue [Figures 1d and e; yellow arrows]. At the S5 level, a stalk extending from the subcutaneous fat into the vertebral canal was noted, but there was no cyst indicating TMCC in it [Figure 1f, blue arrows].
case_images: (Patient 1) (a-c) Microscopic views and (d and e) schematic drawings of the operative findings. Each level of the exposed vertebral arches from L5 to S4 is indicated on (b). (f) Sagittal view of postoperative 3D-hT2WI. Each level of the vertebral columns from L3 to S5 is indicated on (f). (g-i) Photomicrographic composite of the vertical view of the skin and epidural stalk, stained with H&E (g and h) and immunostained for GFAP (i and j). (k-r) Photomicrograph of the axial sections of the cord-like structure stained with H&E (k-m and q) and immunostained for GFAP (n-p and r). CC-LELL with NGT is surrounded by blue arrows on (g), (i), and (k-p). The location of each section is indicated as "gr" in (e). The location of each section is indicated in (e). The location of central canal-like ependyma-lined lumen surrounded by neuroglial tissue in the epidural stalk is indicated as * in (e) and (g-j and k-r). The sites surrounded by dotted line in (g and i) indicate the same site. Higher magnification views of the areas indicated by the square in (g, i, m, and p) are shown in (h, j, q, and r), respectively. 3D-hT2WI, three dimensional heavily T2-weighted image, H&E: hematoxylin and eosin, CC-LELL, central canal-like ependyma-lined lumen; GFAP: glial fibrillary acidic protein, FAT: fibroadipose tissue, FCT: fibrocollagenous tissue, CC: central canal-like structure, and Epen: ependymal cells.
case_images: SNI-14-279-g002.jpg
case_images: PMC10481812_01_SNI-14-279-g002.jpg
case_images: F2
case_images: A skin incision was made to surround the dimple, and a stalk continuous from the subcutaneous fat entered the spinal canal through the myofascial defect [Figure 2a, blue arrows]. The dural sac was exposed through bifid S1-S5, and the stalk entered the dura at the dural cul-de-sac [Figure 2b]. When the dura was opened, the cyst was visible in the rostral part of the C-LS and the caudal part was a lipoma [Figures 2c and d]. The epidural stalk was then cut just distal to the dural cul-de-sac and excised together with the skin lesion [Figure 2e]. MRI performed on the 7th postoperative day demonstrated successful untethering of the cord [Figure 2f]. Histopathologically, the distal side of the epidural stalk, continuing from the skin dimple, was mainly composed of FAT, while the proximal side was mainly composed of FCT [Figure 2g]. The CC-LELL surrounded by glial fibrillary acidic protein (GFAP)-positive NGT was observed in FCT on the proximal side [Figures 2e,*,g-j, blue arrows]. The C-LS was composed of FAT, and the component of FCT increased toward the proximal side [Figures 2k-m]. In addition, CC-LELL surrounded by NGT was observed in these tissues [Figures 2k-r, blue arrows], which increased in size toward the proximal side, and exhibited the form of cystic dilation of CC-LELL at the most proximal side [Figures 2m and p].
case_images: PMC10481812_02
case_images: (Patient 2) (a) Photograph of the skin lesion. (b) Sagittal view of T1WI at the age of 2 months, (c and d) sagittal views of 3D-hT2WI (c) and T1WI (d) at the age of 7 months. Each level of the vertebral columns from L3 to S5 is indicated on (b) and (c). and (e-i) Schematic drawings (e-g and i) and microscopic view (h) of the operative findings. (j) The electrophysiological border between functional conus and caudal lipoma was determined with IONM, by tracing the evoked compound muscle potentials of the external anal sphincter with stimulation of 2 mA, beginning from the functional conus (g-(1)(2)(3)), and proceeding to the caudal lipoma (g-(4)(5)(6)). Stimulation sites are indicated on (g). Each histopathology section is shown in red characters "l-o, p/q". (k) Sagittal view of postoperative 3D-hT2WI. (l-o) Photomicrographic composite of the vertical view of the skin and epidural stalk, stained with H&E (l and n) and immunostained for GFAP (m and o). CC-LELL with NGT is surrounded by blue arrows on (m), (l), (p), and (q). The location of CC-LELL with NGT surrounded by neuroglial tissue in the epidural stalk is indicated as * in (j). The sites surrounded by dotted line in (l and m) indicate the same site. Higher magnification views of the area indicated by the square in (l) are shown in (n and o), respectively. (p and q) Photomicrograph of the cyst wall in the lipoma stained with H&E (p) and immunostained for GFAP (q). The location of each section is indicated as l-o and p, q in (j). T1WI: T1-weighted image, 3D-hT2WI: three-dimensional heavily T2-weighted image, IONM: Intraoperative neurophysiological monitoring, H&E: hematoxylin and eosin, CC-LELL, central canal-like ependyma-lined lumen; GFAP: glial fibrillary acidic protein, FAT: fibroadipose tissue, FCT: fibrocollagenous tissue, cc: central canal-like structure, and Epen: ependymal cells.
case_images: SNI-14-279-g003.jpg
case_images: PMC10481812_02_SNI-14-279-g003.jpg
case_images: F3
case_images: The boy, with joint contractures in the four limbs due to arthrogryposis multiplex congenita, had an abnormal gluteal cleft with skin lesions at birth [Figure 3a]. MRI at the age of 2 months showed a tethered cord with caudal lipoma and syringomyelia in the cord at the L1- L5 of the vertebral level [Figure 3b], and he was referred to us. The second MRI revealed that the caudal lipoma increased in size and extension to the subcutaneous fat through an enlarged sacral hiatus became apparent [Figures 3c and d]. A skin incision was made to surround the skin lesion, and a fatty stalk continuous from the subcutaneous fat entered the spinal canal through the myofascial defect [Figure 3e]. The dural sac was exposed through laminoplastic laminotomy at L5 and bifid S1 to S3, and the epidural lipoma entered the dura at the dural cul-de-sac [Figure 3f]. When the dura was opened, the caudal lipoma and the tethered conus were exposed [Figures 3g and h]. IONM confirmed the existence of an electrophysiological border at the operative microscopic boundary between the two [Figure 3i]. The cyst wall was resected for the histopathological specimen [Figure 3j]. The epidural lipoma was cut just distal to the dural cul-de-sac and excised together with the skin lesion [Figure 3j]. MRI performed on the 7th postoperative day demonstrated successful untethering of the cord [Figure 3k]. Histopathologically, the skin lesion contained clusters of blood vessels beneath the squamous epithelium [Figure 3l, red square] and was diagnosed as angioma. The epidural fatty stalk, continuing from the skin angioma, was mainly composed of FAT [Figure 3l]. In the FAT of the proximal side, CC-LELL surrounded by GFAP-positive NGT was observed [Figures 3j, *, l and m, blue arrows, n and o]. The cyst wall in the lipoma had NGT surrounded by the FCT in the FAT, whereas no CC-LELL was noted [Figures 3p and q, blue arrows].