case_images: PMC11822284_01
case_images: A 53-year-old female with neurovascular compression between the trigeminal nerve and a PTAV and schwannomatosis of the abducens and lower cranial nerves.. A. Axial 3D fast imaging employing steady-state acquisition sequence of the normal appearing right trigeminal nerve (arrowhead) and a vascular loop of the PTAV (arrows) passing through the cisternal segment of the left trigeminal nerve (arrowheads), causing deformity and thinning of the nerve compared to the contralateral side.. B. MR angiography shows the PTAV originating from the left internal cerebral artery, entering the posterior fossa along the medial wall without forming an isolated dural opening, and terminating at the anterior inferior cerebellar artery (arrows) without joining the basilar artery.. C. Contrast-enhanced T1-weighted images show a schwannoma in the left abducens nerve (dashed arrow) and an additional schwannoma involving the lower cranial nerves (glossopharyngeal, vagus, or accessory nerves) (double-dashed arrow).. D. Intraoperative view shows neurovascular compression of the cisternal segment of the left trigeminal nerve by the PTAV (arrow).. E. Microscopic examination of the lower cranial nerve mass (hematoxylin and eosin stain, x100) reveals spindle cells arranged in fascicles, demonstrating nuclear palisading, a characteristic feature of schwannomas.. PTAV = persistent trigeminal artery variant
case_images: jksr-86-185-g001.jpg
case_images: PMC11822284_01_jksr-86-185-g001.jpg
case_images: F1
case_images: Axial 3D fast imaging employing steady-state acquisition (Fig. 1A) and MR angiography (Fig. 1B) images revealed a vascular loop of the PTAV (Fig. 1A, B; arrows) passing through the cisternal segment of the left trigeminal nerve (Fig. 1A; arrowheads), causing displacement and thinning of the nerve compared with the normal-appearing right trigeminal nerve (Fig. 1A; empty arrowhead). This also demonstrated that the PTAV originated from the left cavernous internal cerebral artery (ICA), entered the posterior fossa along the medial wall without forming an isolated dural opening, and terminated at the AICA (Fig. 1B; arrows) without joining the BA. Contrast-enhanced T1-weighted images (Fig. 1C) revealed schwannomas in the left abducens nerve (Fig. 1C; dashed arrow) and lower cranial nerves (glossopharyngeal, vagus, or accessory nerves) (Fig. 1C; double dashed arrow). During surgery, the PTAV (Fig. 1D; arrow) was observed passing through the left trigeminal nerve in the surgical field, and two masses were identified in the left prepontine and cerebellomedullary cisterns. Histopathological analysis of the specimens (Fig. 1E) revealed a pattern consistent with spindle cells arranged in fascicles, along with strong positivity for the S-100 protein, which is a characteristic feature of schwannomas.