![](../pics/biopsy/fhl1/fhl1hehp1a.jpg)
H & E stain
|
![](../pics/biopsy/fhl1/fhl1hehp2a.jpg)
H & E stain
|
Muscle fibers
Small polygonal & angular: Scattered
Very small, basophilic: Few
![](../pics/biopsy/fhl1/fhl1gt2a.jpg)
Gomori trichrome stain
|
![](../pics/biopsy/fhl1/fhl1gt3a.jpg)
Gomori trichrome stain
|
Muscle fibers
Small polygonal & angular: Scattered
Very small: Few
![](../pics/biopsy/fhl1/fhl1nadhlp.jpg)
NADH stain
|
Muscle fibers
Internal architecture: Coarse or irregular
![](../pics/biopsy/fhl1/fhl1nadh2sm.jpg)
NADH stain
|
![](../pics/biopsy/fhl1/fhl1nadh3.jpg)
NADH stain
|
Muscle fibers
Internal architecture: Coarse or irregular
![](../pics/biopsy/fhl1/fhl1cox2.jpg)
COX stain
|
![](../pics/biopsy/fhl1/fhl1cox.jpg)
COX stain
|
Muscle fibers
Internal architecture: Irregular
![](../pics/biopsy/fhl1/fhl1tb1a.jpg)
Toluidine blue stain
|
![](../pics/biopsy/fhl1/fhl1tb2a.jpg)
Toluidine blue stain
|
![](../pics/biopsy/fhl1/fhl1esterase.jpg)
Esterase stain
|
![](../pics/biopsy/fhl1/fhl1estnmjs.jpg)
Esterase stain
|
Esterase stain
Cytoplasm of Small muscle fibers: Dark
Neuromuscular Junctions (Right): Small or Multisegmented
![](../pics/biopsy/fhl1/fhl1atp94lp.jpg)
ATPase pH 9.4 stain
|
Type 2 muscle fibers: Mildly predominant
![](../pics/biopsy/fhl1/fhl1atp94.jpg)
ATPase pH 9.4 stain
|
![](../pics/biopsy/fhl1/fhl1atp43.jpg)
ATPase pH 4.3 stain
|
FHL1: Myopathy (C276Y heterozygous mutation)
![](../pics/biopsy/fhl1/fhl1edhelp1.jpg)
H&E stain
|
Myopathy, Chronic & Severe
Muscle Fibers
Sizes: Varied
Internal nuclei
Connective tissue
Endomysium: Markedly increased
Perimysium: Marked fat replacement
![](../pics/biopsy/fhl1/fhl1edgtmp.jpg)
Gomori trichrome stain
|
![](../pics/biopsy/fhl1/fhl1edhehp1ar.jpg)
H&E stain
|
Muscle Fibers
Myonuclei: Large; Irregular shapes
Cytoplasmic aggregate (Arrow)
![](../pics/biopsy/fhl1/fhl1edhehp2ar.jpg)
H&E stain
|
Muscle Fibers
Vacuole: Irregular shape (Arrow)
Ring fibers + Sarcoplasmic pads (Arrowhead)
![](../pics/biopsy/fhl1/fhl1edhehp3.jpg)
H&E stain
|
Myonuclei
Sizes: Mostly large
Shapes: Irregular
Number: Some fibers have increased numbers, scattered or clustered
![](../pics/biopsy/fhl1/fhl1edhehp4ar.jpg)
H&E stain
|
Muscle Fibers
Irregular cytoplasm structure (Arrow)
Large nuclear clumps
![](../pics/biopsy/fhl1/fhl1edhehp5.jpg)
H&E stain
|
![](../pics/biopsy/fhl1/fhl1edhehp6.jpg)
H&E stain
|
Muscle Fibers
Ring fibers + Sarcoplasmic pads
![](../pics/biopsy/fhl1/fhl1edvvghp2.jpg)
VvG stain
|
![](../pics/biopsy/fhl1/fhl1edampda.jpg)
AMPDA stain
|
![](../pics/biopsy/fhl1/fhl1ednadhmp.jpg)
NADH stain
|
Muscle Fibers
Scattered fibers are small & dark stained
Internal architecture: Coarse
![](../pics/biopsy/fhl1/fhl1edvvghp.jpg)
VvG stain
|
![](../pics/biopsy/fhl1/fhl1edachenmj1.jpg)
Esterase stain
|
Neuromuscular Junctions: Small or Multisegmented
![](../pics/biopsy/fhl1/fhl1edachenmj2.jpg)
Esterase stain
|
![](../pics/biopsy/fhl1/fhl1edachenmj3.jpg)
Esterase stain
|
![](../pics/biopsy/fhl1/fhl1edacp.jpg)
Acid phosphatase stain
|
Histiocytes
Scattered in endomysial connective tissue
Intramuscular nerves: Myelin has increased staining
![](../pics/biopsy/fhl1/fhl1edatp43.jpg)
ATPase pH 4.3 stain
|
Muscle fibers
Type 2 predominance
Scattered Immature (type 2C) fibers
![](../pics/biopsy/fhl1/fhl1edatp94.jpg)
ATPase pH 9.4 stain
|
![](../pics/biopsy/fhl1/fhl1edphal.jpg)
Phalloidin stain
|
Actin (Phalloidin) stain
Actin in muscle fiber cytoplasm is often reduced & irregularly distributed.
![](../pics/biopsy/fhl1/fhl1edphal2.jpg)
Phalloidin stain
|
![](../pics/biopsy/fhl1/fhl1edlama2.jpg)
Laminin-α2 stain
|
Muscle fiber basal lamina
Thick & Irregular around muscle fibers
![](../pics/biopsy/fhl1/fhl1edlama2b.jpg)
Laminin-α2 stain
|
![](../pics/biopsy/fhl1/fhl1edadg.jpg)
α-Dystroglycan stain
|
Muscle fiber basal lamina
α-Dystroglycan is irregularly distributed on muscle fiber surfaces
![](../pics/biopsy/fhl1/fhl1edmhc1.jpg)
MHC I stain
|
Muscle fibers
MHC Class I: Mildly upregulated on muscle fiber surfaces
![](../pics/biopsy/fhl1/fhl1edc5b9.jpg)
C5b-9 stain
|
C5b-9
Stains endomysial capillaries
![](../pics/biopsy/fhl1/fhl1edc5b9b.jpg)
C5b-9 stain
|
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5/8/2023