• Lipofuscin granules: General
    • Yellowish brown
    • Location: Subsarcolemmal region of muscle fibers; Near nuclei
    • Highlighted by
      • Lysosomal stains: Acid phosphatase (Strongly positive); Esterase
      • Oil red O
      • Ferric-ferricyanide reduction test
      • Autofluorescence
    • Ultrastructure: 12 nM granules; Vacuolar
  • Lipofuscin granules become more abundant with
    • Normal
      • Non-dividing cells: Neurons; Muscle (Skeletal, Smooth, Cardiac)
      • Fiber type: More in Types I & IIA than in Type IIB
      • Increasing age
        • Not degraded
        • Accumulate over years
    • Acromegaly
    • Denervation atrophy: Increased concentration in small, denervated muscle fibers
    • Lipid myopathies
    • Chronic obstructive pulmonary disease 1
    • Centronuclear myopathies, adult: Lipofuscin accumulates around nucleus
  • Lipofuscin reduced
    • Active myopathies: Duchenne muscular dystrophy

Acid phosphatase stain

Acid phosphatase stain

Esterase stain

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1. Muscle Nerve 2002;25:383389