Neuromuscular

AMYLOID: PATHOLOGY

Muscle
Nerve
Vessels

MUSCLE


Amyloid myopathy

  • Amyloid (red) is deposited along muscle fiber surfaces and in the perimysium
  • Apple green birefringence of amyloid

Congo red

Congo red (Polarized light)

Congo red (Fluorescence)
Amyloid surrounding, and on, muscle fibers

Congo red

Congo red (Polarized light)

Congo red (Fluorescence)


Congo red

Congo red
Muscle fiber pathology in amyloid myopathy

Congo red

Congo red stain

Congo red stain

Congo red stain (Polarized light)

Congo red, polarized light


Congo red

Amyloid Fibers
  Muscle fiber pathology in amyloidosis

H&E stain

H&E stain

Gomori trichrome

Gomori trichrome

VvG

ATPase pH 9.4

ATPase pH 9.4

NADH


Dystrophin
Surface membrane (Above) & Basal lamina (Below): Thickened & reduplicated around muscle fibers

α2-Laminin

IgAκ M-protein: Amyloid


Congo red
Amyloid deposits in perimysium and along the perimysial surface of muscle fibers

Congo red

NERVE: Amyloid

Patterns of axon loss Amyloid deposition in nerve may be
Severe Axon Loss
Markedly reduced numbers of large and small axons

Neurofilament stain

Neurofilament stain

Moderate axon loss
Differential fascicular loss: More axon loss in some areas than others

Neurofilament stain

Moderate axon loss

VvG stain
More loss of small, than large, axons

Neurofilament stain
Large axons: Moderate loss
Small axons: Severe loss

Neurofilament stain


NCAM stain
Non-myelinating Schwann cells
Normal or Increased Numbers

NCAM stain

Moderate axon loss
More loss of small, than large, myelinated axons



Toluidine blue stain

Toluidine blue stain

Amyloid Deposition

Capillary walls: Thick

H&E stain


Congo red stain
Capillary walls
  Contain red-stained amyloid
  Amyloid is birefringent

Congo red stain

Endoneurial amyloid, Multifocal, often near endoneurial vessels (Arrow)

Congo red stain


Congo red stain

Congo red stain

Toluidine blue stain

Toluidine blue stain

Endoneurial amyloid, Diffuse

Congo red stain

Congo red stain

Toluidine blue stain

Toluidine blue stain

SUBPERINEURIAL AMYLOID (Arrow)

Congo red stain

Moderate sized vessels: Amyloid


Congo red stain

Congo red stain (Polarized light)
Amyloid in vessel wall is stained red. Amyloid in vessel wall is apple green
when viewed with fully polarized light.
View: Amyloid birefringence



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7/16/2016