case_images: PMC11301789_01
case_images: Spinal magnetic resonance imaging revealed an 18-mm tumor lesion with a contrast effect on the ventral side of the foramen magnum (arrowhead); moreover, computed tomography showed no hydrocephalus (Evans index: 0.29).
case_images: SNI-15-231-g001.jpg
case_images: PMC11301789_01_SNI-15-231-g001.jpg
case_images: F1
case_images: The brain magnetic resonance (MR) showed an 18-mm tumor located anterolaterally to the right of the foramen magnum that had enlarged over the past 6 months; there was no accompanying HC [Figure 1].
case_images: (a) Tumor staining image obtained through head angiography. (arrowhead). (b) Tumor staining disappeared due to the embolization of nutrient vessels (arrowhead).
case_images: SNI-15-231-g002.jpg
case_images: PMC11301789_01_SNI-15-231-g002.jpg
case_images: F2
case_images: The cerebral angiogram revealed a tumor stain consistent with a meningioma fed by the right anterior meningeal, right ascending pharyngeal, and left ascending pharyngeal arteries; embolization of the former two vessels was the day before direct tumor resection [Figure 2a and b].
case_images: (a) The right-sided dura was incised, the dentate ligament and the posterior root of C1 were cut, and the tumor was exposed. (b) The tumor was carefully fragmented and completely removed by ultrasonic aspiration. (c) The tumor was completely removed, and the contralateral vertebral artery was identified (arrowhead).
case_images: SNI-15-231-g003.jpg
case_images: PMC11301789_01_SNI-15-231-g003.jpg
case_images: F3
case_images: The tumor was exposed once the dura and dentate ligament were incised, along with retraction of the posterior root of C1 [Figure 3a]. The caudal side of the tumor (i.e., including the ventral portion of the C2 posterior root) was separated carefully from its dural attachments and readily fragmented/aspirated using the SONOPET  (ultrasonic aspirator) [Figure 3b]. Gross total excision was achieved of this lesion which proved histopathologically to be a World Health Organization Grade I meningioma [Figure 3c].
case_images: (a) Spinal magnetic resonance imaging showed complete tumor removal, and computed tomography (CT) showed no hydrocephalus (HC) (Evans index: 0.30). (b) CT showed the appearance of HC (Evans index: 0.36). (c) After lumboperitoneal shunt procedure, CT showed improvement in HC (Evans index: 0.32).
case_images: SNI-15-231-g004.jpg
case_images: PMC11301789_01_SNI-15-231-g004.jpg
case_images: F4
case_images: Three days later, the patient only had a mild residual right lower extremity paresis and the repeat MR confirmed complete tumor removal [Figure 4a]. When the brain computed tomography confirmed the development of HC, a LP shunt was placed [Figure 4b]. Lumbar peritoneal (LP) shunting was performed, which alleviated the patient's symptoms [Figure 4C].