Non-infective Endocarditis
The small pink vegetation on the rightmost cusp margin represents the typical finding with non-bacterial thrombotic endocarditis (or so-called "marantic endocarditis"). This is non-infective. It tends to occur in persons with a hypercoagulable state (Trousseau's syndrome, a paraneoplastic syndrome associated with malignancies) and in very ill persons.
Here is another marantic vegetation on the leftmost cusp. These vegetations are rarely over 0.5 cm in size. However, they are very prone to embolize.
The valve is seen on the left, and a bland vegetation is seen on the right. It appears pink because it is composed of fibrin and platelets. It displays about as much morphologic variation as a brown paper bag. Such bland vegetations are typical of the non-infective forms of endocarditis.
The heart has been sectioned to reveal the mitral valve as seen from above in the left atrium. The mitral valve demonstrates the typical "fish mouth" shape with chronic rheumatic scarring. Mitral valve is most often affected with rheumatic heart disease, followed by mitral and aortic together, then aortic alone, then mitral, aortic, and tricuspid together.
Here are flat, pale tan, spreading vegetations over the mitral valve surface and even on the chordae tendineae. This patient has systemic lupus erythematosus. Thus, these vegetations that can be on any valve or even on endocardial surfaces are consistent with Libman-Sacks endocarditis. These vegetations appear in about 4% of SLE patients and rarely cause problems because they are not large and rarely embolize. Note also the thickened, shortened, and fused chordae tendineae that represent remote rheumatic heart disease.
The small verrucous vegetations seen along the closure line of this mitral valve are associated with acute rheumatic fever. These warty vegetations average only a few millimeters and form along the line of valve closure over areas of endocardial inflammation. Such verrucae are too small to cause serious cardiac problems.
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Pericarditis
This diagram depicts the appearance of a serous pericarditis. The amount of inflammation is minimal, so no exudation of fibrin occurs. The dark stippled dots in the yellow fluid and on the epicardial surface represent scattered inflammatory cells. Serous pericarditis is marked by fluid collection. Rarely, the fluid collection may be large enough to cause tamponade.
This diagram depicts the appearance of a fibrinous pericarditis. The red-pink squiggly lines extending from the epicardial surface into the yellow fluid represent the strands of fibrin. This type of pericarditis is typical of uremia with renal failure, underlying myocardial infarction, and acute rheumatic carditis.
A window of adherent pericardium has been opened to reveal the surface of the heart. There are thin strands of fibrinous exudate that extend from the epicardial surface to the pericarial sac. This is typical for a fibrinous pericarditis.
| This is an example of a fibrinous pericarditis. The surface appears roughened from the normal glistening appearance by the strands of pink-tan fibrin. |
The epicardial surface of the heart shows a shaggy fibrinous exudate. This is another example of fibrinous pericarditis. This appearance has often been called a "bread and butter" pericarditis, but you would have to drop your buttered bread on the carpet to really get this effect. The fibrin often results in the the finding on physical examination of a "friction rub" as the strands of fibrin on epicardium and pericardium rub against each other.
Microscopically, the pericardial surface here shows strands of pink fibrin extending outward. There is underlying inflammation. Eventually, the fibrin can be organized and cleared, though sometimes adhesions may remain.
The pericarditis here not only has fibrin, but also hemorrhage. Thus, this is called a "hemorrhagic pericarditis". It is really just fibrinous pericarditis with hemorrhage. Without inflammation, blood in the pericardial sac would be called "hemopericardium".
The surface of the heart with hemorrhagic pericarditis demonstrates a roughened and red appearance. Hemorrhagic pericarditis is most likely to occur with metastatic tumor and with tuberculosis (TB). TB can also lead to a granulomatous pericarditis that may calcify and produce a "constrictive" pericarditis.
This is a purulent pericarditis. Note the yellowish exudate that has pooled in the lower pericardial sac seen been opened here.
