Inclusion body myositis

Inclusion body myositis (IBM) is an inflammatory myopathy characterized by rimmed vacuoles observed under light microscopy, either subsarcolemmal or centrally within muscle fibers, and filamentous inclusions observed within the sarcoplasm or nuclei under electron microscopy. It is a chronic inflammatory myopathy clinically characterized by progressive muscle weakness and atrophy, predominantly affecting males over 50 years of age.