case_images: PMC9880228_01
case_images: (A) Initial head CT scan showing an ovoid mass with mixed density located in the suprasellar cisterna, compressing the brain stem from the right side. (B) CT angiography suggests negative evidence of vascular lesions.
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case_images: Head computerized tomography (CT) scan, which was performed in the local hospital, showed an abnormal ovoid lesion with mixed density on the right side of the pons and suprasellar cisterna ( Figure 1A ). CT angiography suggested negative evidence of vascular lesions such as an intracranial aneurysm ( Figure 1B ).
case_images: MRI scan at admission. Axial MRI without contrast showing the lesion with heterogeneous hypo-intense on T1-weighted images (A), hyper-intense on T2-weighted images (B), and hyper-intense on T2Flair images (C). Axial (D), sagittal (E), and coronal (F) T1-weighted gadolinium-enhanced images show the heterogeneous contrast enhancement in the inner region of the mass, with a well-circumscribed enhanced cystic wall.
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case_images: With a fluid level inside, the mass measured 29 mm in maximum diameter, compressing the pons and the midbrain from the right anterior direction ( Figures 2A-C ). Besides, the mass demonstrated heterogeneous contrast enhancement in the inner region with a well-circumscribed enhanced cystic wall after administration of the contrast agent gadolinium ( Figures 2D-F ).
case_images: Intraoperative photographs show that the intratumoral hemorrhage is invisible after the incision of the tumor membrane (A). The trochlear nerve tightly adheres to the tumor surface and is assimilated by the tumor (B). Postoperative histopathology shows the characteristic features of a schwannoma complicated with intratumoral hemorrhage and cystic degeneration (C, D).
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case_images: After the evacuation of the hematoma, the tumor was completely removed after amputation of the trochlear nerve and dissection from the surrounding tissues ( Figures 3A, B ). Histopathological examination revealed the characteristic features of a schwannoma complicated with intra-tumoral hemorrhage and cystic degeneration ( Figures 3C, D ).
case_images: CT (A) and contrast-enhanced MRI (B-D) performed after surgery show total removal of the tumor and decompression of the brain stem.
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case_images: Figure 4 ). Four months after the tumor resection, the patient reported that her headache had completely resolved.