[Clinical characteristics and ultra-structural features of skeletal muscle in mitochondrial cytopathies].

OBJECTIVE

To investigate the ultrastructural features of mitochondrial cytopathies and its diagnostic value.

METHODS

Muscle biopsy specimens from 33 cases of mitochondrial cytopathies were examined by routine pathological and electron microscopic examinations.

RESULTS

The main pathologic changes included ragged red fibers in modified Gomori staining, hyper-intense staining myofibers in SDH, COX-negative fibers while dark counterstaining with SDH in COX/SDH double staining technique. Ultrastructural findings included subsarcolemmal and intramyofibrillar proliferation of mitochondria and the appearance of abnormal mitochondria, paracrystalline inclusions, concentric dystrophic cristae and excessive subsarcolemmal glycolipid compounds in subsarcolemmal.

CONCLUSION

The presence of proliferation and abnormality of mitochondria, electro-dense granule and paracrystalline inclusions in mitochondria provide key diagnostic evidence for the diagnosis of this disease.