Neuromuscular

INFLAMMATORY MYOPATHY WITH ABUNDANT HISTIOCYTIC CELLS

Cell Foci Muscle Fibers

IMAM: Lesions

  Locations: Perimysium; May extend into Endomysium
  Cells: Mostly large & Histiocytic; May contain lymphocyte foci

H&E stain

H&E stain

IMAM: Smaller lesion confined to perimysium

VvG stain

IMAM: Vascularization

Cell foci often contain smaller vessels, some with thick basal lamina

VvG stain

Vessels in perimysial cell foci stain for Ulex

UEAI stain

Alkaline phosphatase stain
Vessels in cell foci stain for Alkaline phosphatase & ATPase

ATPase pH 9.4 stain

IMAM: Cell Foci

  Large cells with abundant cytoplasm
  Location: Perimysium > Endomysium


H&E stain



H&E stain



H&E stain
IMAM Cell Foci
  Large cells with abundant cytoplasm
  Location: Perimysium > Endomysium

Gomori trichrome stain


IMAM cells


Congo red stain


Histiocytic cells

  Acid phosphatase positive
  Confluent staining


Acid phosphatase stain

Histiocytic cells:
  May extend from perimysium into endomysium

Acid phosphatase stain

Esterase stain

IMAM cells in perimysium: Contain lipid
  Dark on Sudan
  Gray on VvG


Sudan black

VvG

IMAM perimysial cells: May be PAS positive

PAS stain

IMAM: MHC Class I

Cells in foci: Strong staining
Muscle fibers: Upregulation by morphologically normal fibers

MHC Class I stain

Return to Inflammatory myopathies
Return to IMAM

6/2/2015