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Orbital Myositis

EOM Pathology

H&E stain

Multifocal Inflammatory Myopathy
  Multiple scattered foci of lymphocytes

CD3 (T-cell) stain

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H&E stain

Cell foci: Features of Germinal centers (Ectopic lymphoid structures (ELS)) ¹
  Contain
    Smaller vessels (High endothelial venules)
    B-cells and T-cells
  Locations
    Endomysium: Between muscle fibers
    Perimysium: Between fascicles

H&E stain

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H&E stain

Inflammatory Cells
  In foci
    Common: B-cells & T-cells
    Scattered: Plasma cells
    Few: Eosinophils

H&E stain

H&E stain

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T/B Cell Separation

CD20 (B-cell) stain

B-cells & T-cells: Occupy somewhat different areas in cell foci

CD3 (T-cell) stain

CD20 (B-cell) stain

B-cells & T-cells: Occupy somewhat different areas in cell foci

CD3 (T-cell) stain

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H& E stain

Plasma Cells: Scattered in regions other than lymphocytic foci

CD138 (Plasma cell) stain

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Return to: Normal EOM
Return to Orbital Myositis
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References
1. Nat Rev Immunol 2014;14:447-462, Front Immunol 2016;7:430

11/10/2022