LYMPHATIC LEUNIEMI.A. — By lym phatic or lymphocylic leulcalnia we un derstand the form of the disease in which the lytaphocytic glands, nodes, and structures undergo the hyperplasia. The ' lvinphoeytie structures comprise the lymph-glands and spleen, the lymph nodes of the bone-marrow, the tonsils and subinueous nodes of the intestine, the subcutaneous lymph-nodes, and the scattered lymph-strands seen in all tis sues, especially in the lung, liver, and kidneys. Commonly the hyperplasia af fects the lymph-glands and the spleen; in rare instances it affects most notably the nodes in the skin (dermic leukemia), in tbe intestine (intestinal leukmmia), or in the hone-marrow (osseous leukmmia, or lympliceinia).
The essential lesions consist in an ab normal hyperplasia of the glands or nodes, with the production of au excess of lymphocytes. The glands are much enlarged, soft in the early stages, but later hard from trabecular and capsular fibrosis. licremorrhages may- occur into them. The spleen is usually moderately enlarged, and, as the changes in it are active, the term "spleno-lymphatic" is pathologically correct. A ease of lym phatic leukmia affecting primarily the spleen alone has never been demon strated. The inguinal, axillary, sub clavicular, and cervical glands are the peripheral sites most often affected. The retroperitoneal and mediastinal glands may be enormously enlarged. In the intestinal type the submueous are much enlarged. In the dermie form small lymph-nodes form multiple tumors beneath the skin. In both of these ulcer ations may occur. In the osseous type the marrow presents pale areas resem bling lymph-glands to the naked eye. Microscopically all these structures dis play active proliferation. The cells are polymorphous in type, and degenerations are common. The myelocytes are not in volved in the hyperplasia, but as in any severe anannia the marrow may be spleni fied.
The blood presents a lymplimalia or lymphocytosis. The number of white cells is inueh less than in the myeloge nous type, rarely over 150,000 per cubic millimetre. The excess of cells is com
posed of lymphocytes, large and small, polymorphous in appearance, many pre senting degenerations. The polymor phonuclear leueocytes, the non-granu lated large mononuclear leueocytes, the eosinophiles, and the basophiles are pres ent in normal or even subnormal num bers. Nucleated red cells are rare. The alterations in the number and quality of the red cells are much less than in mye logenous leukmmia.
The secondary lesions are less marked than in myelogenous lenkmmia. The infiltrations are present in the liver, kid neys, pancreas, and to a small extent in the other tissues, but they do not pro duce the marked organic enlargements noted in the other variety. The pig mentary changes are less marked, corre sponding to the lesser degree of hmmol ysis. The fatty and other degenerations are likewise less marked,—as are the luemorrhages.
MIXED LEIJKZEMIA.-By mixed leuke mia we understand the extensions of the hyperplasia to both the myelogenous and lymphocytic structures, and it has been well defined as an "autochthonous hy perplasia of the lymphatic tissues of the entire body," both lymphocytic and leu cocytic. The hyperplasia is more marked in the lymphocytic than in the myelog enous structures. Nearly all the cases are acute in form.
The lymph-glands are not markedly enlarged, they are soft and often have an hmmorrhagic tinge. -Upon section the germ-centers are seen in a state of most remarkable proliferation: there are infiltrations into the vessel-walls and thus a direct flooding of the circulation with the mother-cells of the germ-nests, while the small lymphocytes reach the circulation by the usual channel. The same hyperplasia of the distorted germ nests is seen in the intestinal (where ulcerations are common), in the osseous lymph-nodes, and in the tonsils. The myelocytes are also engaged in abnormal proliferation, though less actively than are the lymphatic cells. Splenification of the marrow is not a marked condition.