BRACHIO-CERVICAL INFLAMMATORY MYOPATHY (BCIM)

Brachio-Cervial Inflammatory Myopathy: Muscle morphology   Myopathic changes & Inflammation
H&E stain	H&E stain
Varied fiber size: Small muscle fibers are rounded Increased endomysial connective tissue	Perivascular inflammation

BCIM: Perivascular inflammation
GT stain	CD20 stain
Perivascular inflammation	Some pervascular cells are B-cells & stain for CD20

BCIM: Histochemistry
Acid phosphatase stain	ATPase pH4.3 stain
Focal invasion of a muscle fiber	Numerous Type 2C immature or regenerating muscle fibers

BCIM: Inflammatory cells
CD4 stain	CD20 stain
CD4 positive mononuclear cells in endomysial connective tissue	CD20 positive B-cells in perimysium & endomysium

CD4 stain CD4 positive mononuclear cells present in endomysium & perimysium	CD20 stain CD20 positive B-cells present in focal regions
Serial sections: B-cell foci are present in some but not all (arrow) regions of CD4 cellularity

BCIM: Complement Deposition (C5b-9; MAC)

C5b-9 stain	C5b-9 stain
BCIM muscle: CD5b-9 components of complement   are deposited in endomysial connective tissue	Control muscle: No CD5b-9 components of complement   are deposited in muscle