case_images: PMC10748725_01
case_images: MRI of skeletal muscle. The figure shows four MRI axial views of pelvic girdle muscle acquired before (a, b) and after (c, d) therapy. The images are T2-weighted sequences with chemical-shift fat saturation obtained at the level of greater sciatic foramen (a) and (c) and at the level of ischial tuberosity (b) and (d). In (a), mild hyperintensity of signal within the muscles gluteus minimun and medium (arrowhead) on the left side can be observed, and it is related to intramuscular edema. After therapy, the edema is significantly reduced (arrowhead in (c)). Similarly, in the more caudal scan, the edema related to the inflammatory process can be appreciated in the left obturator externus, adductor magnus muscles (arrow in (b)) and left gluteus maximum muscle (void arrowhead in (b)). After therapy, the intramuscular edema of obturator externus and adductor magnus is less evident (arrow in (d)) while it is completely resolved in the gluteus maximus (void arrowhead in (d)). The muscle pathologic signal alterations are bilateral but on the right side they result more faint, keeping with the patchy and asymmetrical muscular involvement of the statin-induce myonecrosis.
case_images: CRIM2023-6550473.001.jpg
case_images: PMC10748725_01_CRIM2023-6550473.001.jpg
case_images: fig1
case_images: An MRI scan of the lower limbs showed bilateral intramuscular oedema with patchy distribution involving the gluteus minimus and medius muscles, the insertional area of gluteus maximum, iliopsoas, the adductor magnus, adductor longus, obturator externus, obturator internus muscles, and the central aponeurosis of rectus femoris muscles (Figure 1).
case_images: Histology of skeletal muscle biopsy. (a) Haematoxylin-Eosin (HE) staining shows variation in fibres size and morphology, increased endomyisial connective tissue and several degenerating fibres (arrows). Magnification 20x. (b) Acid phosphatase staining reveals increased activity in the necrotic-degenerating fibres scattered among different fascicles. Magnification 20x. (c) Acid phosphatase staining marks intensively a necrotic fibre with macrophages infiltration. Magnification 20x. (d) Immunoperoxidase reaction with antibody against HLA1/MHC1 complex is present on the necrotic/degenerating fibres. Magnification 20x.
case_images: CRIM2023-6550473.002.jpg
case_images: PMC10748725_01_CRIM2023-6550473.002.jpg
case_images: fig2
case_images: Electromyography showed myopathic changes, whereas muscle biopsy highlighted the presence of necrosis with macrophages infiltration and thickening of connective tissue with mild inflammatory changes (Figure 2).
case_images: Creatine kinase (CK) levels and response to therapy over time.
case_images: CRIM2023-6550473.003.jpg
case_images: PMC10748725_01_CRIM2023-6550473.003.jpg
case_images: fig3
case_images: CK levels completely normalised and upper limb function has fully recovered (Figure 3).