Abscess formation. A, Abscess, lung, cow. A cut section of lung has numerous abscesses. Note the white-to-gray exudate and how it bulges from the cut surface.
Schematic illustration of the TH1- and TH2-mediated chronic inflammation. TH1-(below the blood vessel) and TH2-(above the blood vessel) mediated types of chronic inflammation and some of the key inflammatory mediators, chemokines, and adhesion molecules that mediate the process. CCL, CXCL, Chemokine ligand; ICAM-1,2, intercellular adhesion molecule-1,2; IL, interleukin; INF-γ, interferon-γ; JAM, junctional adhesion molecule; LFA-1, lymphocyte function antigen-1; Mac-1, macrophage-1 antigen; NK, natural killer; PECAM-1, platelet endothelial cell adhesion molecule-1; TNF, tumor necrosis factor; VCAM-1, vascular cell adhesion molecule-1; VLA-4 very late antigen-4.
Diffuse (lepromatous) type of granulomatous inflammation, Johne’s disease (Mycobacterium avium-intracellulare paratuberculosis), ileum, cow.
Mycobacterium avium-intracellulare bacilli. Diffuse (lepromatous) type of granulomatous inflammation with numerous macrophages and multinucleate giant cells that contain abundant bacilli stained red. Acid-fast stain.
Giant cells are a "committee" of epithelioid macrophages. Seen here are two Langhans type giant cells in which the nuclei are lined up around the periphery of the cell. Additional pink epithelioid macrophages compose most of the rest of the granuloma.
These are epithelioid cells around the center of a granuloma. They get their name from the fact that they have lots of pink cytoplasm similar to squamous epithelial cells. Their nuclei tend to be long and stringy.
With a poor immune response to the agents producing granulomatous inflammation, there can be extensive spread of infection with the production of a "miliary" pattern of granulomas, as seen here in the lung of a patient with miliary tuberculosis. The 1 to 2 mm granulomas are scattered around like millet seeds (millet is a type of cereal grain).
Here is a foreign body type giant cell at the upper left of center adjacent to a segment of vegetable material aspirated into the lung. Such foreign body giant cells have nuclei scattered haphazardly about the cell.
Two foreign body giant cells are seen just to the right of center where there is a bluish strand of suture material (arrows) from a previous operation.
Microbial invasion Macrophage stimulation Cytokine production IL-1, IL-6, TNF Loss of appetite Depression Fever Neutrophilia Acute-phase protein response The systemic response of the body to inflammatory stimuli.