PMC8769416_01
Sagittal plane of MRI showing an intramedullary mass lesion associated with the syrinx extending above and below the tumor from C4 to Th4. (A) A T2-weighted MRI showing that the tumor is iso-intense. (B) A T1-weighted MRI showing that the tumor is slightly hypo-intense. (C) A gadolinium-enhanced T1-weighted MRI showing homogenous tumor staining. Axial image T2-weighted MRI at C6-C7 (D) and Th3-4 (E) showing well-demarcated central intramedullary tumor.
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Th4 (Fig. 1A-1E). The tumor was located centrally within the spinal cord and was associated with the syrinx that extended above and below the tumor. The tumor was isointense on T2-weighted MRI (Fig. 1A, 1D, and 1E) and slightly hypointense on T1-weighted MRI (Fig. 1B). Gadolinium-enhanced T1-weighted MRI showed homogeneous tumor staining (Fig. 1C).
(A) Postoperative T2-weighted MRI showing a small amount of residual tumor. (B) A T2-weighted MRI taken 17 months after the first surgery showing that the tumor has grown back from C7 to Th3. (C) A T2-weighted MRI taken 22 months after the first surgery showing enlargement of the recurrent tumor. (D and E) Operated laminar and spinous processes sinking into the spinal canal and compressing the spinal cord at C6-C7 (D) and Th3-4 (E). (F) A T2-weighted MRI taken after the second surgery showing no residual tumors. (G and H) Histopathological examination showing ependymal rosettes and perivascular pseudorosettes, without mitoses, vascular proliferation, or necrosis (hematoxylin and eosin, G: original magnification x100, H: original magnification x200). The tumor had a low Ki-67 index (up to a maximum of 8% in focal areas) and was classified as an ependymoma, WHO grade II. WHO: World Health Organization.
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Postoperative T2-weighted imaging revealed a small amount of residual tumor (Fig. 2A). The tumor had a low Ki-67 index (up to a maximum of 8% in focal areas) and was classified as ependymoma (World Health Organization [WHO] grade II) (Fig. 2G and 2H). However, his ambulation, bilateral leg weakness, and bladder and bowel movements rapidly became exacerbated to the level of modified McCormick Scale Grade IV at 22 months postoperatively as the tumor and associated cyst quickly grew to a considerable size and kyphosis at the cervicothoracic junction obviously progressed because of back muscle weakness (Fig. 2A-2E). T2-weighted imaging showed no residual tumor (Fig. 2F).
Cervical spine radiograph. (A) A radiograph taken preoperatively did not show any signs of kyphosis. (B) He developed severe cervical spine kyphosis 5 months after surgery. (C) A radiograph taken 6 months after the first surgery showing improvement of kyphosis at the cervicothoracic junction brought by placement of cervical collar and lifestyle guidance. (D) A radiograph taken 17 months after the first surgery showing compensatory lordotic curvature of cervical spine with mild cervicothoracic junctional kyphosis. (E) A radiograph taken 17 months after the first surgery showing re-emergence of severe kyphotic deformity secondary to back muscle weakness caused by tumor recurrence.
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However, he started to develop kyphotic deformity at the cervicothoracic junction and compensated cervical lordosis several months after surgery because he spent a lot of time in doing smartphone game with his neck strongly flexed (Fig. 3B). His cervical spine alignment dramatically improved following the instruction (Fig. 3C and 3D) and neurological symptoms recovered in parallel.
CT scans of the spine on the day after the first surgery showing the osteoplastic laminotomy, where the laminae and spinous processes with attaching ligaments were excised en bloc and placed back in with titanium plates, following tumor removal. (A-D) CT image before the second surgery showing kyphotic deformity at the cervicothoracic spine and operated laminae and spinous processes sinking into the spinal canal and compressing the spinal cord. (E-I) This is a schema of the sagittal image of the spine. The kyphotic deformity caused the re-fixed laminar flap (red: spinal process and laminar, orange: posterior ligaments) to come off the residual laminar around 5 months postoperatively as a result of several months of kyphosis. While kyphosis made a significant improvement by placement of cervical collar and lifestyle guidance, plunge of laminar flap into the spinal canal caused by re-emergence of kyphotic deformity accelerated neurological deterioration combined with tumor recurrence.
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A CT scan showed that screws and plates came off the fixed operated laminar flap, which sank into the spinal canal from C6 to Th4 because of kyphotic deformity at the cervicothoracic junction (Fig. 4).