CHAPTER LXX 

 HISTOPLASMOSIS 



Definition — History — ^Etiology — Pathology — Morbid anatomy — Symptoma- 

 tology — Treatment — Refer erxes . 



Definition. — Histoplasmosis is an acute specific infection caused 

 by Histoplasma capsulatum Darling {Cryptococcus capsulatus 

 Darling). 



History. — This disease has been described by Darling, who also 

 found the parasite, but being first discovered post mortem, the 

 clinical signs are rather deficient. The first case was in a negro 

 who, three months previously, had come from Martinique to the 

 Canal zone of Panama. 



-^Etiology. — The disease is caused by the parasite Histoplasma 

 capsulatum Darling, which was at first considered to be a proto- 

 zoon, but is now believed to be a fungus {Cryptococcus capsulatus 

 Darling, p. 1076). 



Pathology. — The parasite infects epithelial and endothehal cells 

 of the lungs, liver, and spleen. It also exists free in these organs. 

 In the lungs it gives rise to pseudo-tubercles resembhng miliary 

 tubercles. 



Morbid Anatomy. — In the first case there were ecchymoses and 

 small nodules beneath the visceral pleura of both lungs, which was 

 studded throughout with pale grey hyaline and miliary tubercles, 

 2 to 3 millimetres in diameter, while the remainder of the organs were 

 of a bright red colour. The peribronchial glands were full of soft 

 caseated tubercles. The heart was small, but normal. The liver 

 was enlarged, pale, and in a condition of shght atrophic cirrhosis. 

 The spleen was enlarged to about three times its usual size, very 

 firm, with distinct Malpighian bodies. The kidneys were shghtly 

 cirrhotic; the pancreas, bladder, bone-marrow, and brain were 

 normal, and no tubercle bacilli could be found. 



Microscopically the lung tubercles were found to consist of 

 alveoli, the walls of which were broken and collapsed, and were 

 filled with alveolar epithelial cells distended with parasites. In the 

 liver the hepatic cells and the vascular endothelial cells were much 

 infected with parasites. Some areas which stained badly were 

 found to consist simply of the debris of cells with numerous para- 

 sites. The spleen showed intracellular and free parasites. 



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