Muscle pathology in DM1. Cross sections of muscle fibers showing with hematoxylin-eosin stain (A) several internal nuclei and size variability, with NADH-TR (B) central nuclei, type 1 fiber hypotrophy and some moth eaten fibers, with Gomori trichrome (C) sarcoplasmic masses, central nuclei and atrophic fibers, with acid ATP-ase (D), type 1 fiber atrophy and type 2 fiber hypertrophy.