case_images: PMC9309486_01
case_images: CNS MRI and the whole-body PET-CT of the patient carried out at the time of admission to the Almazov National Medical Research Centre. (A) Brain MRI (CE T1-WI). Diffuse infiltration of the meninges (soft and hard) of the cerebral hemispheres with uneven thickening and contrast accumulation. (B) Brain MRI (T2*-WI). The area of hemosiderin deposition in the cortex of the right frontal lobe. (C) Brain MRI (T2-WI). Triventricular hydrocephalus. Ventriculoperitoneal shunting (VPS), the shunt in the left lateral ventricle. Severe periventricular edema. Subarachnoid spaces are narrowed. (D) Spinal cord MRI (STIR). The spinal cord at the level of Th8-Th9 vertebrae is thickened, and a spindle-shaped formation of 22 mm x 9 mm x 8 mm is observed. (E) Spinal cord MRI (post-contrast T1-WI). Pia mater of the thoracic region of spinal cord evenly accumulates a contrast agent. The spindle-shaped formation shows no signs of contrast. (F,G) The whole-body [18F]2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18FDG-PET-CT). The picture of diffuse heterogeneous hyperfixation of the radiopharmaceutical along the course of the cervical, thoracic, and lumbar segments of the spinal cord with a maximum value of standardized drug capture of 3.12.
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case_images: F1
case_images: Medical Research Centre, the patient had moderate asthenic syndrome and ataxia. MRI of the brain and spinal cord showed diffuse infiltration of the pia mater and dura mater of the cerebral hemispheres and posterior cranial fossa (PCF) with irregular thickening and contrast enhancement (Figure 1A and Supplementary Figures 1A,B). Supplementary Figures 2A,B). Symmetrical expansion of the lateral ventricles and III ventricle, as well as severe periventricular edema, was detected, while the subarachnoid spaces were narrowed (Figure 1C and Supplementary Figure 3). Th8-Th9 vertebrae was revealed, with hyperintense MR signal on T2-WI and STIR and without contrast enhancement (Figure 1E), which has been regarded as myelitis. The contrast enhancement by the pia mater was noted throughout the thoracic spinal cord (Figure 1E). This PET-CT picture was non-specific and could be observed in both tumor lesions and inflammatory processes (Figures 1F,G).
case_images: CNS MRI of the patient after 5.5 months of the debut of the disease. (A) Brain MRI (post-contrast CE T1-WI). Accumulation of contrast agent by thickened meninges in cerebellar tentorium (green arrows). (B) Brain MRI (T2-WI). (C) Brain MRI (TIRM). Significant increase in cystic lesions of the frontal lobes (green arrows).
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case_images: F2
case_images: Supplementary Figures 2A,B). Symmetrical expansion of the lateral ventricles and III ventricle, as well as severe periventricular edema, was detected, while the subarachnoid spaces were narrowed (Figure 1C and Supplementary Figure 3). The subsequent MRI examinations revealed an increased size of nodular thickenings of dura mater in the area of the tentorium cerebelli (Figure 2A and Supplementary Figures 5A,B); increased cerebral edema in the area of frontal lobes, in the poles of the temporal lobes and cerebellar hemispheres; persisted and progressed diffuse infiltrative changes in the meninges; and increased zones of cystic transformation of the medulla in the cerebellum and frontal lobes (Figures 2B,C and Supplementary Figure 6).
case_images: Immunohistochemical analysis of cortical biopsy. (A) Hematoxylin-eosin staining (H,E). (B-H) Immunohistochemistry using anti-synaptophysin (B), anti-INI1 (C), anti-Ki-67 (D), anti-filamin A (E), anti-beta-catenin (F), anti-Gab1 (G), and anti-MyoD1 (H) antibodies.
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case_images: F3
case_images: Supplementary Figures 2A,B). Symmetrical expansion of the lateral ventricles and III ventricle, as well as severe periventricular edema, was detected, while the subarachnoid spaces were narrowed (Figure 1C and Supplementary Figure 3). As a result of the histomorphological examination, among the fibrous tissue, the complexes of small atypical cells with a narrow rim of the cytoplasm and hyperchromic nuclei were identified (Figure 3A). Tumor cells showed positive staining with antibodies against synaptophysin, MyoD1, filamin A, beta-catenin, INI1, and GAB1 (Figure 3).