Neuromuscular

Lipid myopathy: ETFDH mutations


Capillaries
Degradative
Lipid storage
Mitochondria
Muscle fibers
Ultrastructure
  Lipid
  Mitochondria

ETFDH Lipid Myopathy: Patterns


Sudan black stain


H&E stain
Muscle fibers
  Sizes: Varied, Bimodal
  Contain: Vacuoles, Multiple


VvG stain

Congo Red stain

NADH stain

Sudan black stain

ATPase pH 4.3 stain

ATPase pH 9.4 stain

ETFDH Lipid Myopathy: Muscle Fiber Pathology


H&E stain
Lipid Storage in Muscle fibers
Lipid Droplets: Large size, varied among muscle fibers

H&E stain


Gomori trichrome stain
Lipid Storage in Muscle fibers
Lipid Droplets: Large size, varied among muscle fibers

Gomori trichrome stain

Gomori trichrome stain

Gomori trichrome stain
Storage in Muscle fibers
Other storage material may stain red

Gomori trichrome stain


VvG stain
Lipid Storage in Muscle fibers
Lipid Droplets: Large size, varied among muscle fibers; Some replace entire fibers

VvG stain


Sudan stain
Lipid Storage in Muscle fibers
Lipid Droplets: Large size, varied among muscle fibers

Sudan stain

Sudan stain


ATPase pH 4.3 stain
Lipid Storage in Muscle fibers
Lipid Droplets: More & Larger in Type I (Dark) muscle fibers

ATPase pH 4.3 stain


From: R Schmidt
Lipid droplets
  Many in scattered muscle fiber cytoplasm
  Sarcomeres: Organization is disordered

From: R Schmidt
Lipid droplets
  Many in muscle fiber cytoplasm (Arrow)
  Sarcomeres: Organization is disordered


From: R Schmidt
Lipid droplets
  In muscle fiber cytoplasm (Arrow): Amid proliferated & closely neighboring mitochondria
  Sarcomeres: Scattered; Organization is disordered


From: R Schmidt
Lipid droplets & Lipopigment (Arrow)
  In muscle fiber cytoplasm

ETFDH Lipid Myopathy: Mitochondrial Pathology


Cytochrome oxidase (COX) stain
Cytochrome oxidase (COX) staining
  May be increased or reduced in muscle fibers


Cytochrome oxidase stain
Cytochrome oxidase (COX) staining
  Increased in some muscle fibers

Cytochrome oxidase stain

SDH stain
ETFDH Mitochondria
  Large & Abundant
  Lipid Droplets: Pink staining
  Proliferation in some muscle fibers & capillaries

SDH stain

SDH stain

ETFDH Mitochondria
  Varied degress of proliferation among sarcomeres & lipid droplets in different muscle fibers

ETFDH Mitochondria
  Varied degress of proliferation among sarcomeres in different muscle fibers

ETFDH Mitochondria
  Increased numbers
  Scattered among sarcomeres (Above) or clustered under sarcolemma(Below)

ETFDH Lipid Myopathy: Degradation Pathology


Acid phosphatase stain
Lysosomal Pathology
  Muscle fiber cytoplasm & Some small endomysial cells: Stain for Acid phosphatase

Acid phosphatase stain

Acid phosphatase stain

Autophagic Pathology

LC3 stain
LC3 aggregates in muscle fibers

LC3 stain

ETFDH Lipid Myopathy: Capillary Proliferation & Pathology


VvG stain
Endomysial Capillaries: Increased numbers & Large

Alkaline phosphatase stain
Endomysial Capillaries: Alkaline Phosphatase staining Increased

Alkaline phosphatase stain
Endomysial Capillaries: Alkaline Phosphatase staining Increased

Alkaline phosphatase stain

Endomysial Capillaries: Increased numbers & Large

UEAI stain

UEAI stain
Endomysial Capillaries: Greatly increased numbers & Large size

UEAI stain


Sudan stain
Lipid storage in Vessels
  Intermediate-sized & Endomysial capillaries
(Arrows)

Sudan stain

Endomysial Capillaries
  Mitochondrial Proliferation
(Dark staining; Arrow)
  There is also mitochondrial proliferation in some muscle fibers

SDH stain

Return to: Pathology index

3/22/2021