2<5o LEPROSY. 



face, of the backs of hands and feet, and of the extensor 

 aspects of arms and legs. These nodules enlarge and pro- 

 duce great distortion of the surface, so that, in the case of 

 the face, an appearance is produced which has been 

 described as "leonine." The thickenings occur chiefly in 

 the cutis, to a less extent in the subcutaneous tissue (Fig. 

 69). The epithelium often becomes stretched over them, 

 and an oozing surface becomes developed, or actual ulcera- 

 tion may occur. The cornea and other parts of the eye, 

 the mucous membrane of the mouth, larynx, and pharynx 

 may be the seat of similar nodular deposits. Internal 

 organs, especially the spleen, liver, and testicles, may 

 become secondarily affected. In all situations the change 

 is of the same nature, a sort of chronic inflammatory 

 condition attended by abundant formation of granulation 

 tissue which may be of a nodular character, or more diffuse 

 in its arrangement. In this tissue a large proportion of the 

 cells are of rounded or oval shape, like hyaline leucocytes ; 

 a number of these may be of comparatively large size, 

 and may show vacuolation of their protoplasm and a 

 vesicular type of nucleus. These are often known as 

 "lepra cells." Amongst the cellular elements there is a 

 varying amount of stroma, which in the earlier lesions is 

 scanty and delicate, but in the older lesions may be very 

 dense. Periarteritis is a common change, and very fre- 

 quently the superficial nerves become involved in the 

 nodules and undergo atrophy. The tissue in the leprous 

 lesions is comparatively vascular, at least when young, and, 

 unlike tubercular lesions, never shows caseation. Some of 

 the lepra cells may contain several nuclei, but we do not 

 meet with cells resembling in their appearance tubercle 

 giant cells, nor does an arrangement like that in tubercle 

 follicles occur. 



In the anaesthetic form the lesion of the nerves is the 

 outstanding feature. These are the seat of diffuse infiltra- 

 tions which lead to the destruction of the nerve fibres. In 

 the earlier stages, in which the chief symptoms are pains 

 along the nerves, there occur patches on the skin, often of 



