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Immune Myopathies with Perimysial Pathology (IMPP): PL-12 antibody associated

Also see   IMPP   Dermatomyositis: Adult, IMPP type   Jo-1 muscle pathology

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H&E stain Perimysial cellularity Cells in the perimysium are histiocytic (Above; Arrow). Features include Large nuclei Prominent cytoplasm Staining for Acid Phosphatase, Esterase and CD-68 Fiber size (Below) Perifascicular fibers: May be small Other fibers: Varied sizes, Intermediate or Normal

Acid phosphatase stain Perimysial cells: Acid phosphatase positive   Acid phosphatase

CD4 stain CD4+ cells: Perimysial, & Scattered endomysial

MHC Class I Perifascicular muscle fibers: Express MHC Class I MHC Class I

C5b-9 deposition on Perimysium C5b-9 stain

Varied fiber size: Some small fibers are type 2C ATPase pH 4.3 stain

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Return to Inflammatory myopathies
Return to IMPP


References
1. Curr Opin Rheumatol 2011;23:595-604

2/24/2013