Question
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 |
| B. | Dermatomyositis |
| C. |
Polymyositis |
| D. |
Necrotizing autoimmune myopathy |
|
Correct Answer � B Explanation |
 |
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:
Polymyositis
Primary inflammation with the CD8/MHC-I complex and no vacuoles
Dermatomyositis
Perifascicular, perimysial or perivascular infiltrates and perifascicular atrophy.
Inclusion body myositis
Primary inflammation with CD8/MHC-I complex; vacuolated fibers with β-amyloid deposits