THE LYMPH-NODES. 399 



The reticular tissue may be thickened and the walls of the blood-vessels 

 infiltrated with cells. In this condition the nodes may remain for a long 

 time, not tending to form abscess; or they may undergo resolution 

 through degeneration and absorption of the cells. 



In the tertiary stage of the disease the nodes may be the seat of chronic 

 inflammation characterized by the formation of guinmata. Under these 

 conditions they may form large, firm nodular masses from the growing 

 together by new connective tissue of several altered nodes. The gross and 

 microscopical characters of gummata of the lymph-nodes are, in the main, 

 similar to those in other parts of the body. 



HYPERPLASIA OF THE LYMPH-NODES. (Lymphoma.) 



Iii addition to the considerable enlargements of the lymph-nodes in in- 

 flammation which have been described above, they become enlarged under 

 a variety of conditions which we do not understand. This lack of knowl- 

 edge of the etiology, together with our ignorance of certain functions of 

 the lymph- nodes, and the morphological similarity, or even identity, 

 which these enlarged nodes present under various conditions, render it 

 very difficult to decide upon the exact nature of the change, and in many 

 cases to distinguish one form of enlargement from another. 



In the first place, there is a class of cases in which, sometimes slowly, 

 sometimes with great rapidity, the lymph-nodes of certain regions, espe- 

 cially the abdominal, axillary, cervical, and inguinal, enlarge, not in- 

 frequently to an enormous extent. They may be either hard or soft, even 

 almost fluctuating ; the individual nodes may be distinct or merged into 

 one another. Sometimes the nodes in nearly all parts of the body are 

 affected. Microscopic examination shows, in the soft varieties, a large in- 

 crease of small spheroidal and polyhedral cells and a growth of the retic- 

 ular tissue. It is a new formation of lymphatic tissue, but the normal 

 relations. of follicles, cords, and lymph sinuses are not preserved. In the 

 harder varieties there is a thickening of the reticular tissue in addition to 

 an increase of cells. In rare cases portions of the nodes become uecrotic. 

 Sometimes larger and smaller haemorrhages occur in the nodes, especially 

 in the softer forms. In addition to these changes in the lymph-nodes 

 there is, in a considerable proportion of cases, a new formation of lymph- 

 atic tissue in greater or less quantity in other parts of the body, in the 

 spleen, in the gastro-intestinal canal, in the marrow of bones, in the liver, 

 kidneys, etc., and the number of lymphocytes in the blood and in other 

 parts of the body is increased. This general condition is known as 

 leukcemia and has been considered above, under diseases of the blood and 

 blood-forming organs. The enlarged lymph-nodes in this disease may 

 be called, for convenience, leukcemic lymphomata. 



In the second place, there is a form of disease resembling leukaemia 

 in many respects, particularly in the lesion of the lymph-nodes, usually 

 with a less prominent involvement of the spleen and other lymphatic 

 structures, and, which is more striking, no increase in the number of 



