Lyiuphadcnoina. HodgJdn' s Disease. 383 



Causes. As in leucsemia, no definite cause can be found in the 

 majority of cases. An accessory cause can sometimes be observed 

 where a local irritation gives rise to swelling of the adjacent lym- 

 phatic glands and this goes on to distinct Ijanphadenoma. 



Lesions in the Lymph Glands. The hyperplasia may affect 

 but a single group of glands, more commonly a number of groups, 

 and often nearly all. In one case only of leukaemia in the lower 

 animals, a dog, has Nocard failed to find the lymph glands 

 affected. In the horse he has found the sublumbar glands alone 

 weighing 14.5 kilogrammes, 11 k. and 8 k. They compressed 

 the posterior aorta and vena cava and had caused extensive ascites. 



The enlarged glands are white, gray or in case of rapid growth 

 veined or pointed with red ; they may be soft or firm according 

 as the hyperplasia has operated most on the trabeculae or the cells ; 

 they are homogeneous throughout. The scraping of the cut sur- 

 face gives a more or less thick milky juice containing a great 

 number of nucleated or double nucleated lymphocytes, free nuclei 

 and granules which stain strongly. 



Hardened sections show an enormous development of the 

 follicles at the expense of the medullary walls, and double nu- 

 cleated white globules packed in a rich reticulum of adenoid tis- 

 sue, whilst the blood-vessels in the connective tissue are crowded 

 with white cells, and there are slight ruptures, old or recent. 



Lesions of the Spleen. These are nearly always present. 

 Leisering found a horse's spleen over three feet long and 28 lbs. 

 weight, and Nocard one of 13 lbs. Bollinger found a pig's spleen 

 3^ lbs. Siedamgrotzky found dog's spleens over 2 lbs. The 

 consistency is usually firm (sometimes soft in dog). Capsule 

 thickened and white, cut surface dry, reddish brown, granular, 

 Malpighian bodies enlarged like a pea, hazel nut or walnut, with 

 contents as in the lymph follicles. The capillaries are enlarged 

 and crowded with white cells. 



Lesions in the Liver. The liver is enlarged in one-half of 

 the cases of leukaemia in the lower animals. It has been found 

 to weigh 20 lbs. in the horse, and 4 lbs. in the dog. It is of a 

 grayish brown, or yellowish brown hue, or light red .spotted with 

 yellow, or mapped out by anastomosing grayish white lines. 

 There may be enlargement of the acini, or the formation of little 

 nodes of adenoid tissue, or most commonlj' in the lower animals, 



