TUBERCULOSIS IN MAN 



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can be recognized individually as nodules of a somewhat larger or 

 smaller size than a millet seed. This form is called a miliary tuber- 

 culosis. It is generally due to a simultaneous or gradual distribution 

 of tubercle bacilli by the bloodvessels or the lymphatics of the affected 

 area (hematogenous or lymphogenous infection of an area or organ). 

 General Acute Miliary Tuberculosis. It sometimes occurs that a 

 mass of caseous material breaks into a large lymph channel (thoracic 

 duct) or into a larger bloodvessel, generally a vein, and that tubercle 

 bacilli are disseminated in this manner over the entire body. Miliary 

 tubercles are then formed in almost all of the internal organs of the 

 body and a general acute miliary tuberculosis develops. This is an 

 absolutely and rapidly fatal condition which in man may first be 

 mistaken for an attack of typhoid fever. 



FIG. 149 



Tuberculosis of the pleura in cattle. (Pearl disease.) 



Pearl Disease. The primarily small miliary tubercles usually 

 grow larger, fuse, and in this manner form larger nodules, ranging in 

 size from a pea to a hazel nut. They either become caseous, fibrous, 

 or calcareous, and the entire pleura, particularly in cattle, may be 

 found studded with them. This picture of chronic miliary tuber- 

 culosis in cattle has led to the designation "pearl disease." 



Tuberculosis in Man. Almost every organ or part of the human 

 body may be the seat of a primary tubercular infection. The most 

 common form of tuberculosis in man is the pulmonary. Consumption, 

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