Neuromuscular

PHOSPHORYLASE DEFICIENCY (McArdle Disease)

Vacuoles
No vacuoles
Rhabdomyolysis
Post-Rhabdomyolysis

McArdle Disease: Vacuoles
  Often subsarcolemmal


H&E stain
Subsarcolemmal cytoplasmic vacuoles (Blebs)
  Most contain diffuse pale-staining material
  May contain myonuclei
 

H & E stain
 

 

 

 


VvG stain
Sub-sarcolemmal blebs
  Pale staining of contents on Gomori trichrome
  May contain myonuclei

Gomori trichrome stain


NADH stain
Subsarcolemmal vacuoles


NADH stain


NADH stain

PAS: May stain contents of sub-sarcolemmal blebs, or be diffusely increased in sarcoplasm

PAS stain

McArdle disease: Phosphorylase deficiency
  Absent in muscle fibers
  May be residual activity in vessels

PAS stain

Normal
  Phosphorylase in muscle fiber cytoplasm
  More in type II muscle fibers

PAS stain

McArdle disease: Muscle fibers in regions with few vacuoles


H&E stain
Linear "cracks" in muscle fibers

NADH stain
Linearized pattern of internal architecture: Type 2 > Type 1




Phosphorylase stains


McArdle disease
Some phosphorylase staining is present in vessels &
  regenerating muscle fibers

Phosphorylase stain: Normal

Type II fibers: Darker than type I  

Phosphorylase stain: McArdle's disease

Myophosphorylase deficiency
Muscle fibers stain yellow

Glycogen: PAS stain
  Increased: Diffusely in cytoplasm
  Slightly metachromatic blue color in some areas
  May also stain contents of blebs


Fiber types

Vacuoles: May be in type I or type II muscle fibers


ATPase pH 9.4 stain


ATPase pH 4.3 stain
Immature (Type 2C) muscle fibers are common

ATPase pH 4.3 stain

Phosphorylase Deficiency: Rhabdomyolysis

Necrotic & Hypercontracted Muscle fibers: Scattered

H&E stain

Necrotic Muscle Fibers: Pale; Replaced by histiocytic cells; Hyper-contracted

H&E stain

Necrotic Muscle Fibers: Pale; Replaced by histiocytic cells; Hyper-contracted

Gomori trichrome stain


NADH stain
Necrotic Muscle Fibers
  Pale: Reduced NADH staiining of cytoplasm
  Replaced by histiocytic cells: NADH+ cells in cytoplasm
  Hyper-contracted: Dark-stained cytoplasm

NADH stain

Glycogen in muscle fibers
  Reduced or absent during rhabdomyolysis

PAS stain


Acid phosphatase stain
Histiocytic cells
  Acid phosphatase positive cells invading or replacing scattered muscle fibers
  A few necrotic muscle fibers with pale cytoplasm are not invaded by histiocytes

Acid phosphatase stain

Necrotic muscle fibers: Characteristic pattern of irregular alkaline phosphatase stain around fibers

Alkaline phosphatase stain


ATPase pH 4.3 stain
Scattered small muscle fibers with intermediate staining


Phosphorylase stain
Phosphorylase
  Abesnt in large regions of muscle (Above)
  Other isozymes upregulated in scattered muscle fibers (Below)

Phosphorylase stain

Phosphorylase Deficiency: Post-Rhabdomyolysis


H&E stain
Smaller or Immature Muscle fibers: Scattered
Internal architecture: Cracks & Clefts

H&E stain

Subsarcolemmal Blebs

NADH stain

Post Necrosis
  Residual histiocytic, Acid phosphatase-positive, cells scattered in endomysium

Acid phosphatase stain

Glycogen: PAS positive areas in muscle fiber cytoplasm

PAS stain

Immaturity: Many intermediate-stained (Type 2C) fibers

ATPase pH 4.3 stain

Phosphorylase: Many immature or small muscle fibers express an immature form of phosphorylase

Phosphorylase stain

Also see: Acid maltase deficiency: Adult; Child

Return to Glycogen storage disorders
Return to Muscle biopsies
Return to Pathology images

2/14/2016