INFLAMMATION: Cellular Patterns

GRANULOMAS

H&E stain

Granuloma features Focal collection of cells Histiocytic cells in center Large nuclei Prominent cytoplasm Stain with: Acid phosphatase; Esterase; CD68 antibody Giant cell markers Present: Lysozyme; α1-antichymotrypsin Absent: Myoglobin Lymphocytes in periphery Small dark nuclei Little cytoplasm

Granulomas: Cells stain for   acid phosphatase, esterase & CD68 antigen		CD68 stain
Congo red stain	Esterase stain

H & E stain

Acid phosphatase stain

Focal inflammation: Nongranulomatous
H&E	Esterase
Accumulation of lymphocytes with small dark nuclei (Left) Only a minority of cells are esterase positive (Right)

Chronic granulomatous myopathy

Focal invasion & replacement of a non-necrotic muscle fiber by granuloma cells

Erosion of non-necrotic muscle fibers around their edges

MHC expression by muscle fibers & granuloma cells	Control muscle: MHC expression only in vessels

Other immune features
Alkaline phosphatase staining of perimysium	CD4 staining of granuloma cells

Granuloma in perimysium Congo red

Multinucleated giant cells

Congo red