case_images: PMC11726904_01
case_images: Serial MRI after AVM treatment with SRS showing an enlarging left occipital cystic formation with mass effect and edema. A Axial T2-weighted and B sagittal gadolinium-enhanced T1-weighted MRI 10 years after SRS treatment showed a cystic formation (11 x 16 x 15 mm) surrounded by vasogenic edema, adjacent to a contrast-enhancing angiomatous nodule. C Coronal T2-weighted, D sagittal gadolinium-enhanced T1-weighted, E axial T2-weighted MRI 1 year later (11 years post-SRS treatment) showing a significant enlargement of the cystic formation (70 x 35 x 50 mm), now multiloculated, and of the associated vasogenic edema with contralateral midline shift and incipient subfalcine herniation. The contrast-enhancing angiomatous nodule persists
case_images: 41016_2025_387_Fig1_HTML.jpg
case_images: PMC11726904_01_41016_2025_387_Fig1_HTML.jpg
case_images: Fig1
case_images: Within the cyst, small pseudonodular T2-hyperintense formations were observed (Fig. 1).
case_images: A Organized subacute hematoma embedded in the occipital lobe. B Intraoperative image showing the interior of the xanthochromic cyst and the angiomatous nodule (black arrow) corresponding to the contrast-enhancing area on MRI. C-E Histopathological images of hematoxylin-eosin staining showing dilated vessels with hyalinization of the vascular wall (C black arrow) with the presence of foamy histiocytes (macrophages) in the wall (E black arrow). D Immunohistochemistry showing histiocytes identified with CD-163
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case_images: PMC11726904_01_41016_2025_387_Fig2_HTML.jpg
case_images: Fig2
case_images: A nodular angiomatous lesion was evident (Fig. 2), corresponding to the area of contrast enhancement observed on MRI. An anatomical study of the nodule confirmed the observations described in Fig. 2.
case_images: A Axial T2-weighted, B coronal T1-weighted, C coronal gadolinium-enhanced T1-weighted 1 year post-surgical MRI (12 years post-SRS treatment) showing a left occipital chronic encapsulated expanding hematoma (CEEH) with the persistence of the enhancing angiomatous nodule. Note the contrast-enhancing capsule
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case_images: PMC11726904_01_41016_2025_387_Fig3_HTML.jpg
case_images: Fig3
case_images: Subsequent MRI revealed a subacute hematoma in the region adjacent to the contrast-enhancing nodule, accompanied by vasogenic edema (Fig. 3).