case_images: PMC10921790_01
case_images: Images showing multisystem lesions in the 3-year-old girl with APH. (A-C) MR images showing hypointense on sagittal T1WI (A, thick arrow) and isointense with central punctate hypointense areas on sagittal and axial fat-suppressed sequences of T2WI (B, C, thick arrow). (D-F) Contrast-enhanced T1WI revealing moderate enhancement of the intradural extramedullary nodule, with marked enhancement at the upper and lower rims, accompanied by markedly punctate enhancement in the center on axial (D, thick arrow), sagittal (E, thick arrow), and coronal (F, thick arrow) scans. (G-I) Contrast-enhanced T1WI showing segmentally moderate enhancement of the lesions in the leptomeninges (thin arrow) and the dorsal skin at the L1-2 level (arrowhead) on sagittal (G) and coronal (H, I) scans. Axial contrast-enhanced T1WI showing the changes in leptomeninges and skin lesions before (J, K) and after (L, M) treatment, respectively.
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case_images: PMC10921790_01_fonc-14-1333519-g001.jpg
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case_images: A subsequent MRI examination revealed an oval-shaped nodule (approximately 27 mm x 16 mm x 13 mm) located in the intradural extramedullary space at the T6-T7 level, which was compressing the spinal cord ( Figures 1A-F ). Additionally, there was segmental enhancement of leptomeninges along the cauda equina and lumbar dorsal skin ( Figures 1G-K ). Following four cycles of chemotherapy and a subsequent 20-day treatment with ALK inhibitor (crizotinib), the size of the lesion in the leptomeninges and the skin became smaller on MR images ( Figures 1L, M ).
case_images: Histological and molecular findings from the biopsy of the intradural extramedullary nodule. (A, x100) Hematoxylin and eosin staining showing hyperplasia of eosinophilic histiocytes, accompanied by the expression of ALKA4 (B, x100). (C, x1000) FISH (fluorescence in situ hybridization) analysis using ALK break-apart probe demonstrating the presence of ALK rearrangement with a positive rate of 28%.
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case_images: PMC10921790_01_fonc-14-1333519-g002.jpg
case_images: f2
case_images: Finally, based on histopathological and molecular examination ( Figure 2 ), the case was diagnosed as APH.