A 40-year-old male comes complaining that he is too weak to climb stairs or brush his hair. He denies any headaches or changes in vision. A muscle biopsy reveals perifascicular atrophy. Which of the following is the most likely diagnosis?
|A.||Inclusion body myositis|
Necrotizing autoimmune myopathy
Ans. B. Dermatomyositis
Patient history of proximal muscle weakness and muscle biopsy finding of perifascicular atrophy makes Dermatomyositis the most likely diagnosis.
Muscle biopsy findings:
Primary inflammation with the CD8/MHC-I complex and no vacuoles
Perifascicular, perimysial or perivascular infiltrates and perifascicular atrophy.
Inclusion body myositis
Primary inflammation with CD8/MHC-I complex; vacuolated fibers with β-amyloid deposits