PMC8492430_01
Sagittal images of T2- (a), T1- (b), and Gd-enhanced T1-weighted MRI (c). The tumor mass with iso-intensity on T1-weighted image and mixed intensity on T2-weighted image was located at the T12-L1 level and occupied the spinal canal (arrows).
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F1
Notably, the lumbar MR demonstrated a T12-L1 lesion that was homogeneously enhanced with contrast consistent with a schwannoma [Figure 1].
Axial images of T2-weighted MRI at the level of L1 (a) and L2 (b), and sagittal image of Gd-enhanced T1-weighted MRI (c). The tumor mass (a) markedly compressed the conus medullaris (b) to the right side. The subarachnoid space around the cauda equina (c) just caudal to the tumor mass (a) is densely filled with clots (d), and there is a thick subdural hematoma (e) dorsal to the cauda equina.
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F2
Furthermore, there was intratumoral hemorrhage with SAH/SDH spread resulting in cauda equina compression [Figure 2].
Intraoperative findings (a-d) and illustration by the author (e). (a) When the dura was opened, the tumor was strongly compressing the surrounding cauda equina. Since 3 weeks had already passed since the onset, most of the clot in the subarachnoid space had been washed out. A thick subdural hematoma was present just caudal to the tumor (arrow). (b) When this subdural hematoma was removed, the arachnoid membrane, which had been compressed by the subdural hematoma, was found on its ventral side (arrow). (c) When the arachnoid was opened and the tumor was dissected from the surrounding cauda equina, bleeding from the lower pole of the tumor was found to have extended into the subarachnoid space (arrow). (d) The tumor was totally removed.
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F3
The patient underwent a T12-L2 laminectomy 3 weeks later using intraoperative sensory evoked potential (SEP) and motor evoked potential (MEP) [Figure 3].
Histopathological findings. (a) HE staining. Section of non-hemorrhagic lesion shows a cellular area consisting of elongated cells with Antoni A and B structures. (b) Immunohistochemistry reveals that most of tumor cells are positive for S-100. (c) HE staining. Section of hemorrhagic lesion demonstrates the enlarged, degenerated vessels in the tumor, which are surrounded by the inflammatory cells. (d) Section of hemorrhagic lesion shows fresh hemorrhage with typical Antoni A and B structures.
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F4
Fresh hemorrhage associated with focal necrosis was also found within the tumor [Figure 4].