case_images: PMC11263779_01
case_images: The tumor is composed of malignant spindle cells arranged in fascicles with high mitotic count and necrosis (Hematoxylin and eosin stain, 200X). B. The tumor involves the adjacent thyroid parenchyma (Hematoxylin and eosin stain, 200X). C. The tumor is focally positive for S100 protein indicative of neural differentiation, (S100 protein immunohistochemical stain. 200X)
case_images: aojnmb-02-174-g001.jpg
case_images: PMC11263779_01_aojnmb-02-174-g001.jpg
case_images: F1
case_images: Given the evidence of neural differentiation by immunohistochemistry, the diagnosis of MPNST was confirmed consistent with a high-grade malignant peripheral nerve sheath tumor involving thyroid parenchyma (Figure 1). 
case_images: Positron emission tomography/computed tomography (18F-FDG PET/CT) MIP images demonstrate hypermetabolic lesions in the bilateral thyroid bed, as well as hypermetabolic two left pleural and intercostal soft tissue masses, in addition to soft tissue lesions in bilateral axillary regions and right inferior pelvis
case_images: aojnmb-02-174-g002.jpg
case_images: PMC11263779_01_aojnmb-02-174-g002.jpg
case_images: F2
case_images: Coronal CT (A), PET (B), and fused images (C) demonstrate hypermetabolic two left pleural and intercostal soft tissue masses, as well as, a soft tissue lesion in the right axillary
case_images: aojnmb-02-174-g003.jpg
case_images: PMC11263779_01_aojnmb-02-174-g003.jpg
case_images: F3
case_images: Axial CT (A), PET (B), and fused images (C) demonstrate hypermetabolic residual lesions in the bilateral thyroid bed, which is more prominent on the left side
case_images: aojnmb-02-174-g004.jpg
case_images: PMC11263779_01_aojnmb-02-174-g004.jpg
case_images: F4