Pathology of skeletal muscle: Principles of reaction patterns and histochemistry and experience with 195 biopsies

Abstract

Technique and interpretation of muscle biopsies require the coordinated team work between referring clinician, surgeon, and pathologist so that optimal management of a patient with neuromuscular disease may be attained. Investigation of muscle diseases has advanced so much with an interdisciplinary approach that not only can accurate diagnosis be offered for the benefit of the patient in certain instances, but also genetic counselling provided and pre-natal diagnosis established. The principal reaction patterns and pathogenetic mechanisms of skeletal muscle as a contractile and metabolically active tissue are described; the diagnostic usefulness of enzyme histochemistry and the basic principles of the motor unit are discussed and illustrated. For the practicing pathologist, adequate tissue preparation of a muscle biopsy specimen requires interest and a willingness to dedicate time, effort and funds. While the paraffin-embedded section is still very valuable, enzyme histochemistry provides certain highly diagnostic information not otherwise obtainable. Likewise, there must be an interest in electron microscopy and appreciation for its value in depicting ultrastructural abnormalities when certain reaction patterns are apparent on light microscopic sections, enzyme histochemical stains, or Epon-embedded "thick" sections. Finally, concurrent sural nerve biopsy also requires optimal processing and interpretation.

A novel hindlimb immobilization procedure for studying skeletal muscle atrophy and recovery in mouse

“…While we did not observe a significant increase in centrally located myonuclei in ST TA myofibers, our results clearly indicated that there was an accumulation of nuclei around the myofibers ( Fig. 2A), which may indicate inflammatory cells infiltrate the stromal space during atrophy (32,33). The significant rise in the levels of Sca-1-positive cell population suggested that there was an increase in the density of mesenchymal and inflammatory cells in the myofibers (Fig.…”