OBJECTIVE
To study the clinical and pathological characteristics of inclusion body myositis (IBM).
METHODS
Comprehensive analysis of the characteristics of the clinical, laboratory and pathological of 20 patients with IBM was carried out.
RESULTS
Pathological features of biopsied skeletal muscle, inflammatory cells infiltrated in the perimysium, endomysium or around the blood vessels. Muscle fibers in different size, degenerating, necrotic and regenerating fibers scattered, with connective tissue elements increased. Rimmed vacuoles located in the muscles, with amyloid substance deposited around it. Ragged red fibers (RRF), abnormal distribution and types of muscle fibers. Electronmicroscopically, structure of myofibrils disordered, and Z line derangement or dismissed. In the inclusion bodies of sarcoplasma, many myelin bodies and phagocytic vacuoles aggregated, around with lipid drops and glycogen particle.
CONCLUSIONS
It is difficult to diagnose IBM with clinical features, while skeletal muscle biopsy and pathological analysis is a trustworthy measure for the definite diagnosis of IBM.