case_images: PMC11832630_01
case_images: MRI brain. Axial FLAIR (A), Axial postcontrast T1-weighted MPRAGE (B), Coronal T2-weighted imaging (C). Nodular leptomeningeal tumor deposits are appreciable on FLAIR images as discrete foci of hyperintense signal abnormality within and around the basilar cisterns (green arrowheads in A). The largest tumor deposit (black arrow in A-C) demonstrated central necrosis on post-contrast imaging (black arrow in B) with corresponding hyperperfusion on cerebral blood volume map (not shown). More subtle diffusely disseminated smooth leptomeningeal enhancement is also noted on post-contrast imaging (red arrowheads in B). The extra-axial location of the largest tumor deposit compressing the left dorsal pons (black arrow in A-C) is better demonstrated on coronal T2-weighted images with lesional abutment of the tentorial leaflet (orange arrowhead in C) and encasement of the superior cerebellar artery flow void (blue arrowhead in C). Abbreviations: MRI: magnetic resonance imaging, FLAIR: fluid-attenuated inversion recover, MPRAGE: Magnetization Prepared - RApid Gradient Echo
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case_images: PMC11832630_01_11060_2024_4908_Fig1_HTML.jpg
case_images: Fig1
case_images: These revealed extensive intracranial (Fig. 1) and spinal leptomeningeal enhancement (Fig. 2).
case_images: Axial T1 post-contrast (A), axial FLAIR (B), and coronal T1 post-contrast MRI sequences (C), demonstrating the target lesion (red circle), as an extra-axial, contrast-enhancing, FLAIR-hyperintense nodule. Several additional extra-axial, contrast-enhancing lesions are also evident. (D) Intraoperative photograph of the target lesion (arrow) as viewed through the operative microscope. The lesion resides within the arachnoid meningeal layer, within the Sylvian fissure (S), between the frontal (F) and temporal (T) lobes, which are separated and retracted. Postoperative axial (E), and coronal (F) CT scans, demonstrating a small area of pneumocephalus (red circle), where the biopsy was performed and marked with gelfoam, corresponding well with the preoperative target. Abbreviations: FLAIR: fluid-attenuated inversion recovery, CT: computed tomography
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case_images: PMC11832630_01_11060_2024_4908_Fig3_HTML.jpg
case_images: Fig3
case_images: She had minimal improvement of symptoms despite steroid therapy. She then underwent right pterional craniotomy for identification and open biopsy of a small Sylvian fissure region nodule located between arachnoid and pia (Fig. 3).
case_images: Tumor histopathology and immunophenotype. (A) Low-power view of H&E-stained section shows superficial cortex with a diffusely infiltrating glial neoplasm. (B) High-power view of H&E-stained section shows astrocytic nuclear morphology, mitotic figures (arrowheads), and microvascular proliferation. (C) High-power view of nuclear positivity for Olig-2 protein in many tumor cells. (D) High-power view of elevated Ki-67 proliferation index in tumor. Scale bar = 200microM in panel A, and 50microM in panels B-D
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case_images: PMC11832630_01_11060_2024_4908_Fig4_HTML.jpg
case_images: Fig4
case_images: The tumor involved the superficial cortex and leptomeninges, with a diffusely infiltrative growth pattern (Fig. 4A). Increased mitotic activity and microvascular proliferation were present (Fig. 4B). Tumor cells were positive for Olig-2 (Fig. 4C), and Ki-67 proliferation index was markedly elevated (Fig. 4D).
case_images: PMC11832630_02