case_images: PMC11788329_01
case_images: Magnetic resonance imaging of the patient. (a-c) Magnetic resonance imaging of the extremities was performed at the onset of the disease, showing diffuse muscle involvement. Coronal and axial T2-weighted fat-saturated images of the pelvis and thigh show bilateral symmetrical involvement of the gluteal, pelvic girdle, and thigh muscles (arrows). (d-f) Magnetic resonance imaging performed 1 year after the onset of the disease shows improvement in the patient's extremities.
case_images: fped-12-1522559-g001.jpg
case_images: PMC11788329_01_fped-12-1522559-g001.jpg
case_images: F1
case_images: MB (CK-MB): 100.3 (normal: <3.7) mug/L, myohemoglobin (Mb): 889.6 (normal: 11.6-73.0) ng/ml, erythrocyte sedimentation rate (ESR): 59 (normal: 0-20) mm/h, ferritin: 1:415.2 (normal: 4.6-204.0) ng/ml, and interleukin-6: 16.86 (normal: 0-5.4) pg/ml. Magnetic resonance imaging of the patient's extremities suggested myositis (Figures 1a-c). Magnetic resonance imaging revealed remarkable improvement in her extremities (Figures 1d-f), and the patient tested negative for anti-NXP2 antibody 1 year after disease onset.
case_images: Clinical course and treatment of the patient. Vedolizumab treatment was started at a dosage of 6 mg/kg/dose at 1, 3, and 7 weeks after reoperation. Mp, methylprednisolone; Pred, prednisolone; MMF, mycophenolate mofetil; MTX, methotrexate; IVIG, intravenous immunoglobulin; CyC, cyclophosphamide; PN, parenteral nutrition; CK, creatinine kinase; LDH, lactate dehydrogenase; CK-MB, creatine kinase isoenzyme MB; FC, fecal calprotectin; NXP2, anti-nuclear matrix protein 2.
case_images: fped-12-1522559-g002.jpg
case_images: PMC11788329_01_fped-12-1522559-g002.jpg
case_images: F2
case_images: The patient received combination therapy including prednisone (2 mg/kg/day, gradually tapered), five courses of CyC (500 mg/m2/dose at 4-week intervals), IVIG [2 g/kg/dose x 3, 1 g/kg/dose x 3], oral MTX (7.5 mg weekly), and hydroxychloroquine (HCQ; 100 mg daily) for nearly 5 months (Figure 2).
case_images: (a) Two 5-mm perforations of the transverse colon were observed during surgery. (b) The patient developed an enterocutaneous fistula 10 days after surgery.
case_images: fped-12-1522559-g003.jpg
case_images: PMC11788329_01_fped-12-1522559-g003.jpg
case_images: F3
case_images: During surgery, two 5-mm perforations in the transverse colon were observed (Figure 3a); the perforations were repaired, and an ileostomy was performed. On postoperative day 10, she developed an enterocutaneous fistula (Figure 3b).