Neuromuscular

DYSTROPHINOPATHIES: Becker

Patient < 10 years: Myopathic grouping
Young adult: Moderate severity
Older adult: Late stage
Dystrophin staining patterns


Myopathic grouping

  • Clusters of neighboring necrotic or regenerating muscle fibers all at same stage
  • Most distinctive myopathic change in Becker's muscular dystrophy.
  • Most prominent in patients aged < 12 years
  • Stages

Necrosis: Neighboring muscle fibers (Biopsy from child (< 10 years))
  • Necrotic muscle fibers: Pale on Gomori trichrome, ATPase, NADH
  • Phagocytic cells: Near or within necrotic muscle fibers

Gomori trichrome stain

ATPase pH 9.4 stain

NADH stain

Esterase stain


H & E stain

Esterase stain
Phagocytosis: Clusters of cells (esterase positive) replacing necrotic muscle fibers (Biopsy from child (< 10 years))


H & E stain

Gomori trichrome stain

ATPase pH 4.3 stain


H & E stain

H & E stain

NADH stain
Regenerating muscle fibers: Grouped (Biopsy from child (< 10 years))
  • Size: Small
  • Cytoplasm
    • Basophilic
    • NADH: Dark, irregularly stained
    • ATPase pH 4.3: Stains small muscle fibers
  • Nuclei: Large
  • Also see: Muscle fiber regeneration

Gomori trichrome stain

ATPase pH 4.3 stain

NADH stain


H&E stain

NADH stain
Regenerated, Grouped muscle fibers
  • Immature: Type 2C on ATPase pH 4.3
  • Cytoplasm: Basophilic; Esterase positive
  • Intermediate-sized
  • May have reduced Dys-2 (C-teminal dystrophin) staining


ATPase pH 4.3 stain

Esterase stain

Dys-2 stain

Esterase stain

Post-Regeneration
  • Fiber size: Moderately varied
  • Muscle fiber Cytoplasm: Some fibers with coarse stain on NADH
  • Internal nuclei: Occasional muscle fibers
  • Fiber types: Many 2C
    • Clustered
    • Varied frequencies in different fascicles
  • Endomysial connective tissue: Mildly increased in some areas

H&E stain

Gomori trichrome stain

NADH stain

ATPase pH 4.3 stain

ATPase pH 4.3 stain


Becker Muscular Dystrophy: Biopsy from young adult male

H&E stain

H&E stain




Becker Muscular Dystrophy: Biopsy from adult male

H&E stain

H&E stain

H&E stain

H&E stain

VvG stain
Endomysial connective tissue: Increased

ATPase pH 4.3 stain
Many scattered 2C fibers

Sudan black stain
Endomysium & Perimysium replaced by fat

PAS stain
Normal glycogen

Becker Muscular Dystrophy: Dystrophin staining


Dystrophin gene: Large deletion
Normal control on left panels; Patient on right panels

Dys-3 stain
N-terminus: Staining is present but reduced

Dys-1 stain
Rod domain: Staining is present but reduced

Dys-2 stain
C-terminus: Staining is absent except on a revertant muscle fiber

Dystrophin gene: Leaky stop mutation
Normal control on left panels; Patient on right panels

Dys-3 stain
N-terminus: Staining is present but very reduced

Dys-1 stain
Rod domain: Staining is present but reduced

Dys-2 stain
C-terminus: Staining is present but very reduced


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11/19/2014