i8o PATHOLOGY 



this disease are divided into three stages: the primary, 

 secondary, and tertiary. 



Primary Lesion. In the primary stage there occurs 

 at the site of infection an initial lesion termed chancre. 

 This appears as a small papule or vesicle which is red- 

 dened and inflamed. This soon becomes eroded and 

 surrounded by a zone of infiltration of peculiar hard- 

 ness, termed induration. This consists, histologically, 

 of a diffuse infiltration of round cells, large epithelioid 

 cells, and giant cells. Changes occur in the small 

 arteries and veins, leading to an acute obliterative en- 

 darteritis which causes the peculiar stony induration. 

 The neighboring lymphatic glands undergo hyperplasia 

 and become indurated. 



Secondary Lesions. After a variable length of time, 

 from three weeks to several months, the secondary 

 manifestations of the disease appear. These include 

 swelling and induration of the superficial lymphatic 

 glands. Various eruptions macular, papular, and 

 scaly make their appearance upon the skin. On the 

 mucous membrane occur condylomata or mucous 

 patches, somewhat elevated patches with superficial 

 ulceration or erosion. 



Tertiary Lesions. The most distinctive lesions of this 

 stage are circumscribed tumors, known as gummata, 

 various skin lesions, ulcers, etc., and a peculiar type of 

 arteritis. 



Gummata are nodular masses varying in size from 



