This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Perifascicular atropy of muscle fibres is seen in - 
Select and explain. 
A. Steroid myopathy, B. Dermatomyositis, C. Inclusion body myositis, D. Nemaline myopathy
B: Dermatomyositis
Answer: B: Dermatomyositis 
Explanation: Ans. is 'b' i.e., Dermatomyositis o Dermatomyositis is a connective-tissue disease related to polymyositis that is characterized by inflammation of the muscles and the skin. o It is a systemic disorder that may also affect the joints, the esophagus, the lungs, and, less commonly, the hea. o On the muscle biopsy, there are two classic microscopic findings of dermatomyositis. They are : mixed B- & T-cell perivascular inflammatory infiltrate and perifascicular muscle fiber atrophy. o It is associated with autoantibodies, especially anti-Jol antibody.