Vasculitis: Rheumatoid Disorder/Cryoglobulinemia

Histiocytic Arteritis: Rheumatoid Disorder/Cryoglobulinemia

82 year old female with rapidly progressive mononeuritis multiplex & Multi-organ failure
Rheumatoid factor = 616; ANCA-; NfL 777; C4<4; IgM M-protein; Cryoglobulins, borderline

Vessels
Epineurial: Artery Occlusion
Also see
pANCA
Perimysial: Histiocytic Vasculitis
Nerve Fascicle: Focal Infarction

Nerve: Occluded Artery; Focal infarction

Focal nerve infarction: Also see Behçet

Epineurial Vessel (Artery): Chronic Pathology, Occlusion

Vessel Structure
Damaged wall: Elastin layer interrupted & irregular
Lumen: Absent or Contains large cells, possibly endothelium
Neovascularization
Abnormal staining for NCAM
Size: Large at some levels
Calcification: In some regions of vessels wall
Hemosiderin: Present in Epineurium
Epineurial connective tissue Surrounding vessel: Scattered histiocytes

See: Epineurial vessels, control

Gomori trichrome stain

H&E stain

VvG stain

Alkaline phosphatase stain

VvG stain

Neurofilament (Green) + NCAM (Red)

ATPase pH 4.3 stain

Neurofilament stain

Acid phosphatase stain

Acid phosphatase stain

Cryoglobulin/Rheumatoid Vasculitis: Nerve Infarction

H&E stain

Perineurium: Pale in regions
Endoneurial vessels: Large size & lumen
Epineurium: Increased numbers of small vessels (Above)
Myelin sheaths: Many are abnormally pale-stained (Below)

Gomori trichrome stain

Endoneurial Vessels: Enlarged with large lumen

Toluidine blue stain

Endoneurial vessels: Many are large (Also see below)
Histiocytes with Lipid droplets: Scattered in endoneurium
Myelin remnants (Ovoids): Scattered in endoneurium

Axon Loss

Myelinated Axons: Marked loss
Endoneurial Microvessels: Often large; Some dark stained

VvG stain

Axons, Large & Small: Nearly complete loss
Perineurium: Thick & Irregular structure

Neurofilament stain

Axon & Myelin Degeneration

Myelin sheaths: Abnormal, strong acid phosphatase stain

Acid phosphatase stain

Nerve Infarction: Schwann cell loss in focal regions

Schwann cells, Non-myelinating: Reduced in region of endoneurium

NCAM stain

Neurofilament (Green) + NCAM (Red)

Schwann cells, Non-myelinating (Red): Reduced in regions of endoneurium
Axons: Complete loss in fascicles with loss of Schwann cells

Neurofilament (Green) + NCAM (Red)

Schwann cells (Green & Yellow)
Reduced numbers in region of endoneurium (Left)
"Denervated"" type: Most co-stain for P0 & NCAM (Yellow)

NCAM (Green) + P0 (Red)

Endoneurial Damage: C_5b-9 staining of Endoneurium

C_5b-9 stains
Endoneurium: Cells & Connective tissue
Perineurium: Irregular structure; Thick

C_5b-9 stain

Endoneurial Damage: Hemorrhage

Toluidine blue stain

Endoneurial Cells after Axon loss

From: R Schmidt

Histiocytes
Schwann cells: With myelin & lipid debris
Mast cell
Fibroblast processes

Schwann cells
With Myelin & Lipid debris
Büngner band components

From: RSchmidt

Epineurial Damage

Alkaline phosphatase stain

Alkaline Phosphatase
Stains: Connective tissue around nerve; Epineurium

Alkaline phosphatase stain

Cryoglobulinemia/Rheumatoid Disorder: Muscle

Vessel Structure: Damaged

See: Perimysial vessels, control

H&E stain

Perimysial Vessels (Arteries)
Size: Very large
Wall Structure
Inner layer: Fibrinoid necrosis
Outer layer: Replaced by large, "palisaded" cells
Lumen: Large cells, possibly endothelium, adherent to inner wall