Histopathology of Skeletal Muscle Mitochondria

The muscle biopsy can often be one of the most decisive steps in the diagnosis of several mitochondrial diseases, even when the patients do not exhibit any apparent clinical symptom of muscular involvement. The technique is particularly efficient in the case of respiratory chain deficiencies. The histological examination of this muscle biopsy is perhaps the best technique for visualizing rare muscle fibers which exhibit striking mitochondrial anomalies. Indeed, in biochemical studies which are generally performed with muscle homogenates, it is difficult to distinguish differences between normal and diseased tissue when, for example, 10% of the fibers are damaged.