Orbital Myositis
EOM Pathology
![](../pics/biopsy/inflammation/orbmyositis/ocmyositisinflphe5.jpg)
H&E stain
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Multifocal Inflammatory Myopathy
Multiple scattered foci of lymphocytes
![](../pics/biopsy/inflammation/orbmyositis/ocmyositisinfcd3lp.jpg)
CD3 (T-cell) stain
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![](../pics/biopsy/inflammation/orbmyositis/ocmyositisinflphe3.jpg)
H&E stain
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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
![](../pics/biopsy/inflammation/orbmyositis/ocmyositisinfmphe3.jpg)
H&E stain
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![](../pics/biopsy/inflammation/orbmyositis/ocmyositisinfveshphe.jpg)
H&E stain
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Inflammatory Cells
In foci
Common: B-cells & T-cells
Scattered:
Plasma cells
Few: Eosinophils
![](../pics/biopsy/inflammation/orbmyositis/ocmyositisinfhphe4.jpg)
H&E stain
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![](../pics/biopsy/inflammation/orbmyositis/ocmyositisinfhphe3.jpg)
H&E stain
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T/B Cell Separation
![](../pics/biopsy/inflammation/orbmyositis/ocmyoscd20a.jpg)
CD20 (B-cell) stain
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B-cells & T-cells: Occupy somewhat different areas in cell foci
![](../pics/biopsy/inflammation/orbmyositis/ocmyoscd3a.jpg)
CD3 (T-cell) stain
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![](../pics/biopsy/inflammation/orbmyositis/ocmyoscd20b.jpg)
CD20 (B-cell) stain
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B-cells & T-cells: Occupy somewhat different areas in cell foci
![](../pics/biopsy/inflammation/orbmyositis/ocmyoscd3b.jpg)
CD3 (T-cell) stain
|
![](../pics/biopsy/inflammation/orbmyositis/ocmyositisinfplasmahe.jpg)
H& E stain
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Plasma Cells: Scattered in regions other than lymphocytic foci
![](../pics/biopsy/inflammation/orbmyositis/ocmyositisinfcd138lp.jpg)
CD138 (Plasma cell) stain
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Return to:
Normal EOM
Return to
Orbital Myositis
Return to
Neuromuscular home page
References
1.
Nat Rev Immunol 2014;14:447-462,
Front Immunol 2016;7:430
11/10/2022