Tissue reactions in selected granulomatous diseases
THE CONTEXT
Granulomatous diseases differ in their causes, inflammatory cell composition, and patterns of necrosis.
Syphilis
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The syphilitic gumma has a surrounding wall of macrophages and a plasma cell infiltrate. Central cells are necrotic but retain their cellular outlines.
Cat-scratch disease
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Cat-scratch disease is caused by infection with Bartonella henselae, a gram-negative bacillus.
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Its granulomas are rounded or stellate and contain central granular debris and recognizable neutrophils. Giant cells are uncommon.
Sarcoidosis
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Sarcoidosis has an unknown etiology and produces noncaseating granulomas containing abundant activated macrophages.
Crohn disease
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Crohn disease is an inflammatory bowel disease associated with an immune reaction against intestinal bacteria and possibly self antigens.
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Occasional noncaseating granulomas occur in the intestinal wall with a dense chronic inflammatory infiltrate.