Neuromuscular

Mitochondrial disease: Cytochrome oxidase deficiency, Children

1 month old child
6 month old child

COX Deficiency: 6 month old child



H&E stain
Muscle fibers with "Cracks" & Small, round holes

Gomori trichrime stain

"Checkerboard" pattern of fiber types
  "Cracks" & Small round holes are more prominent in type I (pale) fibers

ATPase, pH 9.4

Type 2C (Immature; Intermediate-staining), muscle fibers: Increased numbers (> 5%)

ATPase, pH 4.3


Sudan black
Large lipid droplets in many fibers

Toluidine blue

Toluidine blue

Cytochrome oxidase
  Reduced staining in all fibers

COX stain

COX stain

Succinate dehydrogenase (SDH)
  Increased staining in many fibers

SDH stain

SDH stain

COX Deficiency: 1 month old child



COX stain
Cytochrome Oxidase (COX) is diffusely reduced in muscle fibers

COX stain
Cytochrome Oxidase (COX) is diffusely reduced in muscle fibers, but preserved in
  Perimysial vessels (Arrow)
  Intrafusil spindle fibers

COX stain


SDH stain
Succinate Dehydrogenase (SDH) is mildly increased in some muscle fibers (Arrow)

SDH stain

Type 2C muscle fibers (Intermediate staining): Increased numbers

ATPase pH 4.3 stain

Lipid Droplets: Increased size

Sudan black stain

Glycogen (PAS staining) is increased in muscle fibers

PAS stain

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2/17/2023