Neuromuscular

TNFα Inhibitor Myopathy

General pattern
Endomysium
  Inflammation
  Cell types
Muscle fibers
  Incomplete fusion
  Necrosis
Perimysium

General pattern
  Necrotic muscle fibers: Scattered
  Perimysial connective tissue: Damage & Cellularity

H&E stain

ENDOMYSIAL CELL PATHOLOGY

Muscle fibers
  Necrotic & Regenerating: Scattered; Varyied stages

H&E stain


H&E stain
Inflammation
  Endomysial: Lymphocytes
  Perimysium: Histiocytes

H&E stain

H&E stain

Congo red stain
Inflammation
  Lymphocytes: Endomysial
  Histiocytes: Replacing necrotic muscle fibers

VvG stain

VvG stain

ENDOMYSIAL IMMUNE CELLS

CD4 stain
CD4 & CD8 cells in endomysium

CD8 stain

PERIMYSIAL PATHOLOGY

H&E stain
Perimysial structure: Damaged & Irregular
Immune cells: Large cells with abundant cytoplasm in perimysium

H&E stain
Perimysial structure: Damaged & Irregular

Gomori trichrome stain

Immune cells: Focus in perimysium

H& E stain

Perimysial pathology
  Abnormal staining of perimysium for alkaline phosphatase

Alkaline Phosphatase stain

Staining of cells in perimysium, and scattered in endomysium, for acid phosphatase

Acid Phosphatase stain

CD4 cells: In perimysium & endomysium

CD4 cell stain

MUSCLE FIBER PATHOLOGY

VvG stain
Incomplete fusion of regenetating muscle fibers with larger, neighboring fibers

VvG stain

VvG stain

VvG stain
Incomplete fusion of regenetating muscle fibers with larger, neighboring fibers

VvG stain


ATPase pH 4.3 stain
Unfused muscle fibers: Type 2C with intermediate staining on ATPase pH 4.3

ATPase pH 4.3 stain

ATPase pH 4.3 stain

ATPase pH 4.3 stain

Internal architecture: Irregular; Dark staining in center fo some fibers

NADH stain

Immature small unfused muscle fibers: Stain for alkaline phosphatase

Alkaline phosphatase stain


Caveolin-3 stain
Immature small unfused muscle fibers
  Surface stained for Caveolin-3
  Caveolin-3 staining is darkest at region near neighboring larger muscle fiber

Caveolin-3 stain

Caveolin-3 stain

Caveolin-3 stain

Caveolin-3 stain


Decorin stain
Basal lamina (Decorin-stained)
  Dark surrounding areas of small & large muscle fibers
  Pale at region near neighboring larger muscle fiber

Decorin stain

Decorin stain


C5b-9 stain
C5b-9
  Muscle fiber surface: Irregular deposits
  Necrotic muscle fiber: Cytoplasm

C5b-9 stain


MHC Class I stain
MHC Class I: Upregulated on all muscle fibers

MHC Class I stain

Muscle fiber necrosis & regeneration

VvG stain
Necrotic muscle fibers
  Replaced by histiocytic cells
  Pale on NADH & ATPase stains

NADH stain


ATPase pH 9.4 stain

Gomori trichrome stain
Necrotic muscle fibers: Replaced by histiocytic cells

VvG stain


ATPase pH 4.3 stain
Immature muscle fibers
  Type 2C: Intermediate-stained on ATPase pH 4.3
  Dark-staind on NADH

NADH stain

NADH stain

Immature muscle fibers: Small basophilic fibers atg edge of fascicles

H& stain

Autophagic aggregates: Muscle fiber cytoplasm

LC3 stain

Endomysial capillaries: Enlarged

UEA I stain

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5/14/2016