case_images: PMC11726623_01
case_images: PMC11726623_02
case_images: PMC11726623_03
case_images: Muscle morphological studies. Deltoid muscle biopsy was performed at ages 53, 37, and 59 in patient 1, 2, and 3, respectively. Cross-serial sections. Patient 1 (a-d): H&E (a) and mGT (b) showing an abnormal fiber (the same fiber is indicated by a star) harboring multiple subsarcolemmal vacuoles containing some granular/dotted material appearing fuchsinophilic with mGT staining. Marked fiber size/diameter variation is also evident. (c) MAC/C5b9 immunostaining shows the presence of granular complement deposition at the sarcolemma in several fibers. (d) Electron micrograph shows the presence of an abundant subsarcolemmal membrane vacuolization formed by different compartments separated by redundant membrane layers. Autophagic material and cellular debris filled the vacuoles. Scale bars: 20 mum (a-c), 2 mum (d). Patient 2 (e-h): H&E (e) and mGT (f) show a few fibers (one of the fibers is indicated by a star) with multiple subsarcolemmal vacuoles. (g) MAC/C5b9 immunostaining shows the presence of granular complement deposition at the sarcolemma in a few fibers. (h) Electron micrographs showing a completely disrupted muscle cell containing autophagic material with myelinic profiles, cellular debris, and prominent proliferation of reticular structures. Scale bars: 20 mum (e-g), 2 mum (h). Patient 3 (i-l): H&E and mGT (P and S) show a few fibers with multiple subsarcolemmal as well as central vacuoles containing slightly granular material, variations in fiber size and diameter, and rare internalized nuclei. (k) MAC/C5b9 immunostaining shows the presence of granular complement deposition at the sarcolemma in three fibers. (l) The ultrastructural analysis shows multiple sarcoplasmic vacuolization. Scale bars: 20 mum (i-k), 2 mum (l).
case_images: ENE-32-e70026-g002.jpg
case_images: PMC11726623_03_ENE-32-e70026-g002.jpg
case_images: ene70026-fig-0001
case_images: Deltoid muscle biopsies (Figure 1) revealed a homogenous histological phenotype showing a vacuolar myopathy with numerous non-rimmed vacuoles containing amorphous material (Figure 1a-j). I was negative, and C5b9/MAC showed the presence of scattered fibers with granular sarcolemmal deposits (Figure 1c,g,k). Immunofluorescence studies using antibodies against kappa- and lambda-light chains, performed on patient 1's muscle biopsy, failed to show the presence of kappa-light- or lambda-light-chain-positive immunoreactive material in non-vacuolated or vacuolated muscle fibers or muscle vessels.
case_images: Muscle MRI and 18FDG-PET scan studies in patient 3 at age 68. Muscle MRI of pelvic girdle (a) and thigh (b): fatty degeneration of gluteus, biceps femoris, semimembranosus, semitendinosus, biceps femoris, and adductors sparing gracilis. At the leg level (c), note fatty infiltration of the posterior compartment (soleus, gastrocnemius medialis, gastrocnemius lateralis) sparing tibialis posterior. 18FDG-PET scan (d) shows increased symmetric FDG uptake in both proximal and distal muscles of all four limbs (arrows).
case_images: ENE-32-e70026-g001.jpg
case_images: PMC11726623_03_ENE-32-e70026-g001.jpg
case_images: ene70026-fig-0002
case_images: In patient 3, muscle MRI (Figure 2), performed 9 years after the beginning of the neurological history, showed at pelvic and thigh level a diffuse fatty infiltration of the posterior compartment of the thighs, sparing the gracilis muscle, and at leg level a diffuse fatty infiltration of the posterior compartment, sparing the tibialis posterior. 18F-fluorodeoxyglucose (18FDG) PET scan showed a marked symmetric homogenous FDG uptake in the neck, four limbs, and abdominal muscles in patient 3 (Figure 2).