IPLab:Lab 9:ARF

Images

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  This is a gross photograph of mitral valve demonstrating marked thickening and fibrosis of the valve leaflet. There are also numerous foci of fibrinoid necrosis within the cusps and friable vegetations (verrucae) along the lines of closure (arrows). These irregular, warty projections are found at sites of erosion on the inflamed endocardial surface. The verrucae probably result from the precipitation of fibrin where the leaflets impinge on each other.

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  This is a low-power photomicrograph of heart tissue. Little can be seen at this magnification, except that the tissue looks relatively normal.

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  This is a higher-power photomicrograph of myocardium showing cellular accumulations--Aschoff bodies (arrows)--within the interstitium of the myocardium. These are found especially around blood vessels.

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  This is a higher-power photomicrograph of myocardium containing Aschoff bodies (arrows) within the interstitium.

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  This high-power photomicrograph of myocardium shows the cellular detail of an Aschoff body. Aschoff bodies are foci of fibrinoid necrosis surrounded by lymphocytes, macrophages, an occasional plasma cell, and plump “activated” histiocytes called Anitschkow cells or Aschoff cells (arrows). These distinctive cells have abundant amphophilic cytoplasm and central round-to-ovoid nuclei in which the chromatin is disposed in a central, slender, wavy ribbon resembling a caterpillar (hence the designation “caterpillar cells”).

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  This high-power photomicrograph of myocardium shows the cellular detail of another Aschoff body. In this case there appears to be a multinucleated Aschoff giant cell (arrow).