Hydroxychloroquine Myopathy
Hydroxychloroquine Myopathy
Scattered muscle fibers with: Vacuoles; Aggregates; Basophilic cytoplasm; Small size

H&E stain
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H&E stain
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Muscle fibers
Vacuoles
May be internally clear, or contain basophilic aggregatesd material
May be
Acid phosphatase positive
May contain:
Lipofuscin-like granules;
Granular material
Internal nuclei
LAMP2 granules

H&E stain
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H&E stain
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Muscle fibers
Vacuoles

H&E stain
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Muscle fibers
3 small muscle fibers with vacuoles & red staining of cytoplasm.
Fiber sizes: Intermediate to Very small
Vacuoles
Borders: Irregular
May contain: Aggregates; Clustered & lipofuscin-like material

Gomori Trichrome stain
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VvG stain
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Muscle fibers
Vacuoles: Gray-Black rims & Aggregates

VvG stain
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Lipofuscin-like material: In vacuoles & cytoplasm

Congo red stain
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Congo red stain
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Muscle fibers
Vacuoles: Contain lipofuscin-like material

Congo red stain
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Esterase stain
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Muscle fibers
Vacuoles: Contain lipofuscin-like material

Esterase stain
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Lysosomal material in muscle fibers: Acid phosphatase & LAMP-2 staining

Acid phosphatase stain
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Acid phosphatase stain
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Acid phosphatase stain
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Acid phosphatase stain
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Acid phosphatase+ Regions
Location: Present in vacuoles & cytoplasm

Acid phosphatase stain
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LAMP-2 stained organelles

LAMP2 stain
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Aggregates in muscle fibers

Toluidine blue stain
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Hydroxychloroquine Myopathy: Ultrastructure
Aggregates: Contain Heterogeneous Material
Membrane-bound vacuoles
Curvilinear bodies
Degradation products
Lipid & Lipofuscin structures
Membranous whorls
Mitochondria

From: R Schmidt
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Curvilinear bodies (Arrow)
Lysosome-derived cytoplasmic inclusions
Also occur in
ceroid lipofuscinosis

From: J Chen
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Curvilinear bodies & Complex lipid structures with globular elements

From: J Chen
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From: R Schmidt
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From: R Schmidt
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Complex Lipid Structures

From: R Schmidt
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From: R Schmidt
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Autophagic Degradation Products

From: J Chen
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Membranous Whorls

From: J Chen
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From: R Schmidt
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Membrane-bound vacuoles
? Lysosomal

From: R Schmidt
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From: R Schmidt
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Vacuoles: Surrounded by Mitochondria

From: R Schmidt
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Hydroxychloroquine Myopathy: Mitochondria
Scattered tubular cristae

From: R Schmidt
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Neuropathy: Hydroxychloroqine-associated

Toluidine blue stain
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Neuropathy
Large axons
Loss
Thinly myelinated
Regenerating axon clusters
Endoneurial vessels: Thick walls

Toluidine blue stain
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Return to
Hydroxychloroquine myopathy
Return to
Muscle biopsies
12/3/2024