case_images: PMC11165051_01
case_images: Pre-operative Magnetic Resonance Imaging (MRI). Axial T2-weighted (left), coronal fluid-attenuated inversion recovery (FLAIR) (middle), and sagittal T2-weighted (right) scans showing a neoformation arising from the hypoglossal nerve (white arrows).
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case_images: f1
case_images: T2 hyperintensity due to some contextual hyperintense areas in T2 ( Figure 1 ). The mass displaced the internal carotid artery anterolaterally and exerted modest compression posterior to the internal jugular vein, with a slight increase in the caliber of the upstream sigmoid sinus.
case_images: Intraoperative Images. Intraoperative close-up view before (left) and after (right) tumor excision through an oblique incision at the level of the right sternocleidomastoid muscle in the supine position (A = carotid artery, B = jugular vein, C = nerve bundle, X = tumor).
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case_images: f2
case_images: The portion of the tumor posterior to the internal carotid artery and anterior to the internal jugular vein was adequately identified ( Figure 2 , left). Excision was macroscopically completed ( Figure 2 , right).
case_images: Histopathological Images. Microscopic image (left) and S100 positivity image (right) of a hypoglossal schwannoma taken through a 10x objective on hematoxylin and eosin-stained histological sections.
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case_images: PMC11165051_01_fonc-14-1400335-g003.jpg
case_images: f3
case_images: A histological examination confirmed the radiological suspicion of a schwannoma, as the morphophysiopathological picture was consistent with a schwannoma originating from the hypoglossal nerve (S100+, calretinin+, SOX10+, D240+, and Ki67 5%) ( Figure 3 ).
case_images: Post-operative Magnetic Resonance Imaging (MRI). Axial T2-weighted (left), coronal FLAIR (middle), and sagittal T2-weighted (right) post-operative MRI scans demonstrating complete excision of the hypoglossal schwannoma at 6-month follow-up.
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case_images: PMC11165051_01_fonc-14-1400335-g004.jpg
case_images: f4
case_images: Although a six-month follow-up period is relatively short for investigating possible relapse in such a pediatric case, there were no signs of tumor recurrence at a follow-up MRI performed six months after surgery ( Figure 4 ), and the patient was in excellent general condition.