Neuromuscular

NEMALINE RODS

Nemaline rod myopathy: Infantile

 
Gomori trichrome

Nemaline rods in gastrocnemius muscle from 4 month old child



No nemaline rods in quadriceps muscle from same child biopsied at 2 months of age

Nemaline rod myopathy, Infantile: Toluidine blue stains

Nemaline rod myopathy, Infantile: Other stains


H& E stain

Variable muscle fiber size
Refractile rods can be seen
ATPase stain, pH 9.4

Type I muscle fiber predominance

Nemaline rod myopathy, Childhood


GT stain

Rods in smaller muscle fibers
ATPase stain, pH 9.4

Type I muscle fibers: Smaller than type II

Rods in adult nemaline myopathy

 
Gomori trichrome

Nemaline Rod Ultrastructure


From E Hardeman

Electron microscopy of rods from Z-lines
in Met9Arg αTMslow mouse

Nemaline Rod Pathology

  • Light microscopy: Rods best visualized with Gomori trichrome stain (Upper Left)
  • Dark red-blue structures in muscle fiber cytoplasm
  • Composed of Z-line like material (Upper Right)
  • Contain α-actinin & tropomyosin ± desmin at the periphery
  • Located in sarcoplasm: Often in regions with disrupted sarcomere structure
  • Occur in
    • Congenital myopathies
    • Adult onset nemaline myopathies
    • Muscle fibers with targets

  • Also see: Rods in target fibers
  • External link - Canine rod myopathy

Return to Rod myopathies

3/14/2004