case_images: PMC9333131_01
case_images: Magnetic resonance imaging results showing abnormality (A-D). Increased signal intensity could be detected in both T1-weighted (A, B) and T2-weighted with fat suppression (C, D) images, indicating muscle atrophy and edema. The pelvic muscles and inner and posterior muscles of both thighs were affected heavily. Pathology studies of the skeletal muscle showing amyloid deposits (E-J). Muscle biopsy obtained from the patient showing slight myofibers atrophy on hematoxylin and eosin (H&E)-stained section (E). Weak congophilic deposits within the blood vessel walls in Congo red-stained section visualized under light microscopy (F, G, black arrow). lambda light chain immunofluorescent staining showed a positive staining in blood vessel walls and perimysium (H, white arrow), and the perimysium involvement was not detected in Congo red staining. kappa light chain immunofluorescent staining showed a negative result (I), indicating a lambda light chain restriction. Congo red-stained specimen viewed via polarized microscopy revealed positive apple-green birefringence of amyloid deposits (J, white arrow). Magnifications (x): 100 in (E, F, H, I); 400 in (G, J).
case_images: fonc-12-914379-g001.jpg
case_images: PMC9333131_01_fonc-12-914379-g001.jpg
case_images: f1
case_images: Magnetic resonance imaging (MRI) revealed atrophy and edema in proximal lower limbs and pelvic muscles ( Figures 1A-D ). Immunofluorescence staining showed a lambda light chain restriction in both blood vessel walls and perimysium, which is strongly positive in blood vessel walls but weakly positive in the perimysium ( Figures 1E-J ).
case_images: Time and events of the case report. The level of creatine kinase considerably dropped after the initiation of CyBorD regime chemotherapy and is within the normal range at present. Hematological remission was also achieved soon after chemotherapy. Clinical symptoms were alleviated after six cycles of chemotherapy.
case_images: fonc-12-914379-g002.jpg
case_images: PMC9333131_01_fonc-12-914379-g002.jpg
case_images: f2
case_images: A considerable reduction in CK level was detected during treatment ( Figure 2 ).