PMC3424685_01
Preoperative T1-weighted (a, c) and T2-weighted (b, d) magnetic resonance images without gadolinium enhancement demonstrating an intradural extramedullary cystic tumor at the T1-T2 level. (a, b) Sagittal view and (c, d) axial view
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F1
T1-T2 level that was severely compressing the spinal cord from the ventral side [Figure 1]. T1- and T2-weighted MR images [Figure 1]. The tumor showed no enhancement on gadolinium-enhanced T1-weighted MR images. There were no other abnormal findings including vertebral body anomalies, spina bifida, or a mediastinal mass.
(a) Intraoperative photograph of the cyst wall. (b, c) Paraffin section of the intraoperative frozen sample (H-E staining; scale bars represent 50 mum); (b) a magnified view of the region in the square in panel (c)
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F2
After the spinal cord was longitudinally split along the posterior median sulcus, the cyst wall, which had a thin, translucent, membranous appearance, was identified at the ventral side of the flattened spinal cord through the split posterior median sulcus [Figure 2a]. The cyst was aspirated with a 24-gauge elastic needle [Figure 2a]. The intraoperative pathological diagnosis with frozen sections was an arachnoid cyst [Figure 2b and c, see below for details].
(a, b) T2-weighted magnetic resonance images at 1 day (a) and 10 months (b) after the first surgery. (c) Contents of the cyst. (d) Intraoperative photograph of the second operation showing a cyst-subarachnoid shunt tube inserted into the cyst
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F3
Postoperative MR imaging demonstrated marked shrinkage of the cyst [Figure 3a]. However, 10 months after surgery, the patient noted precordial oppression again, and MR imaging revealed that the cyst had refilled [Figure 3b]. Eleven months after the first operation, fenestration of the cyst wall and insertion of a cyst-subarachnoid shunt were performed using the same approach as the first operation [Figure 3d]. The contents of the cyst were again similar to that of the CSF [Figure 3c], and contained 18 mg/dl protein, <1 mg/dl glucose, 153 mmol/l sodium, 3.0 mmol/l potassium, and 135 mmol/l chlorine. One end of the shunt tube was inserted into the cyst through the split posterior median sulcus, and the other end was placed in the dorsal subarachnoid space of the spinal cord [Figure 3d].