MORBID ANATOMY.—There may be extreme wasting. Dropsy of the feet is common, and ascites may be present.
A noteworthy feature is the full amount of blood in the heart and blood-vessels, usually in the form of large coagula. In one case (XI.) the weight of clots alone in the heart-chambers, not including what came from the veins, was 620 grammes. The portal, cerebral, pulmonary, and subcutaneous vessels were also greatly distended with clots. The portal vein just above the union of the branches measured eleven centimeters in circumference.
The blood is usually clotted in the heart and vessels, and the aggregation of the colorless corpuscles densely infiltrating the fibrinous clots and the serum gives a pus-like appearance, so that it has not infrequently happened, as in Virchow's memorable case, that the observer on opening the right auricle believed for the moment that he had cut into an abscess. The leukæmic clots often have a peculiar greenish color, and resemble somewhat the fat of the turtle. Similar coagula may fill the veins of the brain and abdominal viscera. The tendency of the white corpuscles to aggregate together, and the subsidence of the red to the lower part of the heart-chambers and vessels, may give an appearance of more intense leukæmia than actually exists. The reaction of the blood is usually acid. The chemical constitution has been carefully studied, but with no very satisfactory results. Hypoxanthine, lactic acid, leucin, tyrosin, a mucin-like body, and a gelatinous substance have been described, but none of them may be regarded as characteristic of the disease. The octahedral crystals are thought by some to be tyrosin,132 but Schreiner133 says they consist of the phosphate of an organic base, the composition of which is not yet settled.
132 Huber, Archiv der Heilkunde, Bd. xviii.
133 Liebig's Annalen, cxciv.
The specific gravity of the blood is lowered, 1036 to 1049. The water is increased. The fibrin in many observations has also been found increased; 4.8 per 1000 was the average of ten observations by Bennett. The albumen and the salts have not often been estimated. The former is stated to be diminished. The fatty bodies have been found in excess of the normal quantities.
The heart is often pushed up by the large spleen; the pericardium, more rarely the endocardium, may present ecchymoses, and the fluid may be in excess. In a few instances leukæmic growths have been met with. The chambers are usually distended, the walls soft, and a moderate grade of fatty change is very common. No special alteration has been met with in the blood-vessels. I have seen extensive fatty degeneration of the intima and small arteries.
In the great majority of cases the spleen is increased in size, but the shape is retained. It is usually of a deep violet-red color, and strong adhesions may unite it to the abdominal wall, diaphragm, or stomach. The capsule may be greatly thickened, forming a firm fibro-cartilaginous investment. The vessels are enlarged, particularly the veins at the hilus. The weight may vary from two to eighteen pounds. The largest on record is given by Langley Browne134—18½ pounds. Six or seven pounds is an average weight. The length may vary from seven to twenty inches, and the breadth eight to twelve. The organ is in a condition of chronic hyperplasia—hard, firm, cuts with resistance, and displays a uniform reddish-brown surface on which the trabeculæ are more or less prominent. There may be hemorrhages or infarcts, and it is not uncommon to see regions of yellow or rusty-brown staining, indicating where an extravasation had occurred. As a rule, no trace of the Malpighian bodies can be seen. Grayish-white, circumscribed lymphoid tumors may occur throughout the organ, contrasting strongly with the reddish-brown matrix. The process of gradual enlargement is a simple hyperplasia. In the early stage, not often seen, there is swelling of the pulp, increase in the cell-elements, without the firmness and induration of the fully-developed leukæmic organ. Rupture may occur at this period from the intense hyperæmia. The Malpighian bodies are enlarged and prominent by their grayish-white color. A gradual and progressive induration results from the increase in the adenoid network and the fibrous trabeculæ. A section shows the enormous development of the fibrous elements. The cells may be scanty, only two or three in meshes, or, indeed, the reticulum may be so close that only a single cell is enclosed. As a rule, the hyperplasia extends over the whole organ, and the Malpighian bodies become involved and lose their distinctness. In only one of the cases which I have examined were they at all prominent. Leukæmic new growths in the spleen are rare.
134 Lancet, 1877, ii.
Uncomplicated cases of the lymphatic form are very uncommon: usually they enlarge with the spleen, and in the majority of instances the hypertrophy is not extensive, scarcely ever reaching the high grade seen in Hodgkin's disease. The groups of cervical, axillary, mesenteric, and inguinal are most frequently affected; the bronchial and mediastinal but rarely. The bunches of glands are not usually larger than walnuts, moderately soft, isolated, movable; large matted groups do not often occur. They may vary a good deal in size during the course of the disease, often diminishing notably before death. In chronic cases they may become very indurated. The leukæmic lymphadenitis is a simple hyperplasia, and the soft glands may look, on section, of a normal gray color or may have a deep gray-red appearance. Hemorrhages may occur, and twice I have seen the enlarged glands deeply hyperæmic. Histologically, the appearance is very like a normal gland, only the lymph-spaces are more closely packed. In the harder glands the fibrous reticulum is much increased, the capsule thickened, and the section more grayish in color. Caseation or suppuration rarely occurs, and invasion of contiguous parts is most exceptional.