case_images: PMC10993731_01
case_images: Magnetic resonance imaging [MRI; (A) T2-weighted imaging (T2WI); (B) T1-weighted imaging (T2WI)] reveals that there are fusiform soft tissue masses with low signal on T1WI and high signal on T2WI under the skin of the proximal tibia on the left and the distal tibia on the right, of which boundaries are clear. Contrast-enhanced T1WI sequence scan after contrast agent injection [(C) Coronal; (D,E) Axial; (F) Sagittal view shows small nodules of markedly enhanced soft tissue in the middle of the left calf (arrows)] revealed significant enhancement in both lower extremity lesions.
case_images: fmed-11-1346647-g001.jpg
case_images: PMC10993731_01_fmed-11-1346647-g001.jpg
case_images: fig1
case_images: Low-limb magnetic resonance imaging (MRI) showed fusiform low-signal soft tissue swelling at the proximal and distal ends of the right tibia subcutaneously, with clear boundaries and significant enhancement after the injection of contrast agent, showing increased signals in lower limb lesions (Figure 1).
case_images: 18F-FDG PET/CT [(A,a) Maximum intensity projection (MIP)] was subsequently performed to further evaluate the patient's whole-body condition and revealed multiple nodules of hypermetabolic uptake in the lumbar spinal canal (black arrow) and lower limbs (white arrows). Besides, multiple high metabolic nonspecific lymph node uptakes were observed in the mediastinum (asterisk arrow). Tomographic images show multiple soft tissue density nodules with high FDG uptake on the lateral side of the right ischial tuberosity [(B) CT; (C) PET/CT fusion; arrows], upper thigh [(D) CT; (E) PET/CT fusion; arrows], middle [(F) CT; (G) PET/CT fusion; arrows] and lower left thigh [(b) CT; (c) PET/CT fusion; arrows], upper [(d) CT; (e) PET/CT fusion; arrows] and middle leg [(f) CT; (g) PET/CT fusion; arrows; SUVmax 7.5], and lower right leg [(h) CT; (i) PET/CT fusion; arrows]. In addition, isomuscular signal on T1WI (H, arrow) and high metabolic uptake nodule on PET/CT (I, arrow) were also observed in the posterior spinal canal of the first lumbar spine.
case_images: fmed-11-1346647-g002.jpg
case_images: PMC10993731_01_fmed-11-1346647-g002.jpg
case_images: fig2
case_images: The results showed that multiple 18F-FDG uptake nodules increased in the first lumbar vertebra, the lateral side of the right ischial tuberosity, the upper part of the thigh, the lower part of the left thigh, and the right calf (Figure 2).
case_images: (A) Histological examination shows tumor cells are spindle-shaped, bundle-shaped, and focal fence-shaped (hematoxylin-eosin stain, original magnification x100). Immunohistochemistry shows that tumor cells positively express PGP9.5 (B), S100 (C), and vimentin (D).
case_images: fmed-11-1346647-g003.jpg
case_images: PMC10993731_01_fmed-11-1346647-g003.jpg
case_images: fig3
case_images: The histopathological results showed that these tumors had the same pathological properties and were all schwannomas (Figure 3).