Muscle Biopsies

Either needle or surgical biopsies are submitted. All are processed for conventional EM but only a select number are ultimately examined by EM. The bulk of the samples are observed by LM from 0.5 µm transverse and longitudinal sections stained with methylene blue.

Muscular Dystrophy (muscle degeneration) and myopathies can be identified from these sections. Hereditary, progressive, degenerative, metabolic and non-inflammatory conditions (e.g. Duchenne disease, glycogen storage disease, mitochondrial aberrations, honeycomb structures and triads) can be observed by EM. In addition, structural changes take place in the muscle fiber involving myofibrils, nuclei, mitochondria and membranes. These structural alterations cannot be usually linked to a specific condition but the changes in some instances follow a pattern that implies a particular disorder (Mair and Tome 1972).

Electronmicrographs of muscle biopsies

Normal muscle	Myelin Bodies	Glycogen deposits
Mitochondrial deposits	Muscular Dystrophy	Honeycomb