22,3 Goodpasture: The Histology of Healing Yaws 269 



Large mononuclear phagocytes are present in great numbers 

 and are not confined to the papillae but are to be seen in consider- 

 able abundance in interepithelial spaces, engulfing leucocytes 

 wherever they find them. The cytoplasm of many is filled with 

 the digesting remains of these cells, and they are present in no 

 less abundance in the corium where they are also engaged in 

 phagocytic activity, picking out only polymorphonuclear cells 

 which lie among plasma cells and lymphocytes in a number ex- 

 ceeding that of the previous lesion. These active cells are 

 removing leucocytes rapidly from the lesion, not only by local 

 digestion but by transportation, as is indicated by their presence 

 in dilated lymphatics; otherwise, there is no observable change 

 in the cellular exudate. Eosinophiles are present, as in the 

 previous lesion, but they are not being phagocytized. Small 

 accumulations of fibrin at the tips of certain papillae are invaded 

 by mononuclear cells which have assumed the shape and ap- 

 pearance of epithelioid cells. Some of the vessels of the papillae 

 contain fibrin thrombi thus invaded. 



Levaditi preparation. — These sections show no treponemata. 

 It thus appears that following injection of neosalvarsan tre- 

 ponemata are rapidly destroyed and disappear from the lesion. 

 With the removal of this active pathogenic agent reparative 

 processes immediately ensue. 



Four months previously the mother yaw developed on a finger. 

 One month later secondary lesions appeared over the entire 

 body, accompanied by swelling and pain over bones and joints. 

 Lesions on arms, legs, and feet were only macules and dried up ; 

 those on the face, neck, chest, and hands have grown to be typical 

 yaws measuring 0.5 to 2 centimeters in diameter, elevated and, 

 when first seen, moist and semitranslucent, having a yellowish, 

 honeylike surface. Ten days later, at the time of removal of the 

 first lesion, they are still soft but more opaque, yellow, and mot- 

 tled, with small haemorrhages. 



Yaw 1. — September 1. A yaw measuring 1.5 centimeters in 

 diameter having the above-described yellow, purulent, and hae- 

 morrhagic appearance was excised by Doctor Franco from the 

 left side of the back after the injection of novocaine about its 

 margins. The yaw was totally removed with a portion of 

 corium beneath. Sections 1 millimeter thick were immediately 

 fixed in 10 per cent formalin and in Zenker's fluid. 



