PMC9177165_01
Preoperative images.
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Computed tomography showed high- and low-density areas with a maximum diameter of 31 and 34 mm, respectively, in the right and left cerebellum (a). T1-weighted (b), T2-weighted (c), and T2*-weighted MR (d) images showed the lesions with mixed signals. Perifocal edema was observed around the periphery, and T2WI and T2*WI showed a low-signal ring sign around the lesions. Enhanced CT showed no obvious abnormal blood vessels or tumor (e). 3DCTA showed cerebral aneurysm in the right distal ACA; however, no apparent vascular lesion was identified in the posterior fossa (f).
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Computed tomography) showed areas with a maximum diameter of 31 and 34 mm, respectively, in the right and left cerebellum that exhibited high- and low-density patches and were more mottled than in a typical cerebellar hemorrhage (Fig. 1a). The lesions showed a mix of high and low signals on T1 WI, T2 WI in MRI, and perifocal edema was observed around the periphery (Fig. 1b, c). Additionally, multiple cystic lesions with low signal in the interior as well as T2 WI and T2* WI low-signal ring signs around the lesions were observed (Fig. 1c, d). Because of the need for urgent decompression surgery, only contrast-enhanced CT and 3D-CTA were performed to rule out vascular or neoplastic lesions, which did not show any of these findings (Fig. 1e, f).
PMC9177165_02
PMC9177165_03
Operative view.
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The operative view of the lesion of the left side. It showed a thin capsule that could easily rupture, and a reddish-brown old hematoma was drained from the interior when the capsule was breached.
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These vessels were cauterized and cut, and the lesion was extracted (Fig. 2).
Postoperative images taken after transferring to our hospital.
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CT scan taken the next day of the operation showed that both lesions have been removed and external decompression was performed (a). T1-weighted MRI images taken 1 month (b) and 2 months (c) after the operation showed no recurrent cerebellar lesion.
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The volume of the posterior fossa was enlarged with an artificial dura mater, the bone flap was not put back in place, and surgery was completed with external decompression (Fig. 3a). No recurrent cerebellar lesion was observed on CT and MRI taken 1 or 2 months later (Fig. 3b, c).
Pathological findings.
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Multiple capillaries in hematoma considered to be secondary changes in response to hematoma. No tumor cells or vascular lesions were found. Hematoxylin and eosin stain x 20 (a), hematoxylin and eosin stain x 40 (b), and capillaries were shown using ERG immunostaining (c).
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Pathological findings showed multiple capillaries in hematoma, which can be taken as the possibility of secondary changes in response to hematoma (Fig. 4a-c).