Part 56

LEUKÆMIA. LEUCOCYTHÆMIA.

Definition. Nature. Result of other morbid processes. Leucocytes polynuclear. Lymphatic leukæmia. Spleno-myelogenous leukæmia. Leucocytes in each. Loss of amœboid movement. Charcot’s crystals. Hæmatoblasts. Cell increase in bone marrow. Myelocytes. Enlarged spleen and lymph glands. Hæmorrhages. Lymphoid growths. Susceptible genera. Causes obscure. Symptoms, pallor, listlessness, weakness, apnœa, sweating, thirst, emaciation, weak circulation, anæmic murmur, enlarged spleen, bleedings, diarrhœa, dropsy, excess of white globules, reduction of red globules, buffy coat, beaten fibrine is granular, china-white mucosæ, hurried breathing, stertor, deranged digestion, marasmus. Duration. Not inoculable. Treatment, not hopeful, as for anæmia, good hygiene, tonics, stimulants, antiseptics.

Definition. An excessive and persistent increase of the white blood globules, and associated with enlargement of the spleen, lymph glands or bone marrow.

Nature. This must be distinguished from the leucocytosis which occurs during digestion, or that which attends on tuberculosis, glanders, pneumonia, and other extensive inflammations and profuse suppuration. These forms are transient and the cells are of the polynuclear variety. The cells of leukæmia are various in character, but bear some relation to the particular organ which is the seat of hypertrophy or morbid process.

“In =lymphatic leukæmia= the increase in the number of leucocytes is due to the mononuclear lymphocytes, especially of the small form. As many as ninety-five per cent. of the colorless cells may be of this form. In =Spleno-Myelogenous leukæmia= the eosinophile cells may be especially increased in number, and there are also large leucocytes coming apparently from the marrow of the bones, and called myelocytes. These most nearly resemble the larger lymphocytes of normal blood, but they are usually larger. They have a single large nucleus which stains feebly and their bodies may show neutrophile granules. Larger and smaller nucleated red blood cells may be found in spleno-myelogenous leukæmia. The leucocytes are frequently in a condition of fatty degeneration, and there may be a decrease in the number of red blood cells.” (Delafield and Prudden). In splenic leucocythæmia blood plates may be absent and in lymphatic leucocythæmia they may be in excess.

Cafavy claims that many of the leucocytes have lost their active amœboid movements.

Bright white crystals in the form of elongated octahedra are found not only in the blood but in the diseased glands, spleen or marrow (Charcot’s crystals). Clusters of discoid hæmatoblasts (blood plates) are present in the blood in variable numbers (Schultze’s granule masses).

The bone marrow is marked by an accumulation of spheroidal cells, which tend to pass into a condition of fatty degeneration. Most of them are colorless, larger than the lymphocytes of normal blood and have one large often vesicular nucleus, staining less highly than the lymphocyte nuclei, and with neutrophile granules in the protoplasm (=myelocytes=). There are besides, nucleated red blood cells, spheroidal cells, containing red blood cells, and Charcot’s crystals. The marrow may be uniformly red, mottled gray and red, gray, grayish yellow, or puriform (Delafield and Prudden). This may affect one or many bones. The affected spleen is usually much enlarged, at first uniformly, later unevenly, firm or softened, and with thickened white capsule. The cut surface is smooth, brownish red, or yellow, with white lines (thickened trabeculæ) and indistinct Malpighian corpuscles. It contains glutin, glycocoll, hypoxanthin, zanthin, leucin, tyrosin, and lactic, acetic, or formic acids.

The affected lymph glands are somewhat enlarged, red or gray, exceptionally, softened or caseated and otherwise contain an excess of leucocytes.

Slight hæmorrhages may appear in any of these structures. Lymphoid growths may appear in a number of other organs as the liver, heart, lungs, kidneys, bowels, tonsils, the different blood glands, the serosæ and the retina.

Genera affected. It has been seen mainly in dogs, but also in horse, ox, pig, cat and mouse. Nocard has collected the following cases: horse 9, cattle 6, pig 5, dog 22, cat 1.

Leisering found a horse’s spleen weighing 28 kilogrammes. Johne found a pig’s spleen of 2.4 kilogrammes.

Causes. The primary causes of leukæmia are unknown. As in anæmia all unhygienic conditions are invoked as causes. That it is not due to simple hypertrophy or irritation of the leukogenic centers is plain, as it does not follow on ordinary diseases and injuries of these parts, but what is the precise nature of the morbid cause has so far eluded us.

Symptoms. Pallor of the visible mucous membranes, listlessness, lack of energy and endurance, breathlessness and perspiration on the slightest exertion, ardent thirst, rapidly advancing emaciation, unsteady gait, stiffness or lameness, lies most of the time, walks with pendent head, and jaws open, small, weak pulse, anæmic murmur in the heart, enlarged lymph glands, or spleen felt beneath the left lumbar transverse processes in the ox, or in the left hypochondrium in the horse. Bleeding from the nose or elsewhere, slight hæmorrhage into the conjunctiva, irritable conditions of the bowels, diarrhœa and dropsies are suggestive. The blood when obtained in epistaxis or drawn by a needle prick may be pale rose, brownish or grayish brown instead of red, and under the microscope shows the enormous excess of leucocytes—the ratio to the red being sometimes 1: 2, or even more, in the human subject. In the domestic animals the following ratios have been made by actual count: 1: 85 (Leblanc and Nocard), 1: 50, 1: 45 (Mauri), 1: 20 (Nocard), 1: 15 (Siedamgrotzky), 1: 12 (Forestier and Laforque). The normal average for the domestic animal according to Nocard is 1: 900. This great relative excess of white globules serves to distinguish this malady from anæmia, and its persistency is a means of diagnosis from transient leucocytosis.

The red globules are always reduced in number in the horse and dog to 5,082,000, and even 2,050,000 per cubic millimetre, while the normal is 7,500,000 (Nocard).

In clotting, the blood forms an extensive buffy coat, and in solipedes which normally show this, the blood set in a test tube forms three strata, the upper slightly yellow, semi-transparent and formed of fibrine; a median of a dull, opaque white color and formed mainly of leucocytes and blood plates, and a lower of a violet red and formed mainly of red globules.

The amount of fibrine is variable. It becomes granular when beaten. Albumen is variable but usually reduced.

The visible mucous membranes are bloodless and of a clear porcelain white. The walk becomes weaker, fore feet wide apart and the hind limbs partly flexed, head and neck extended, and breathing labored. The breathing may be with constant stertor, the bowels torpid and tympanitic, or loose and fœtid, dropsies and hæmorrhages ensue, and the patient dies in complete marasmus.

Duration. The disease may prove fatal in less than a month, or it may last for three, six, or eight months. It is mostly fatal.

Not inoculable. Many attempts have been made to transmit it by inoculation, but in no case with success.

Treatment is not successful. All hygienic measures should be adopted, as for anæmia; open air and sunshine, with protection against chills; the treatment of all complications; iron, bitters, phosphorus, arsenic in particular, electricity to the spleen, massage; oxygen inhalation; and locally, iodide of potassium or mercury, generally and locally.

LYMPHADENOMA. HODGKIN’S DISEASE.

Definition. Relation to leukæmia. Causes. Mainly accessory. State of lymph glands, spleen, liver, bone marrow, intestine, tonsils, thymus, kidneys, liver, lungs, bronchial mucosa, pleura, pericardium, nervous system. Symptoms, as in leukæmia, with adenoid hyperplasia, but little leucocythemia. Relation to glanders. Uric acid, low density, no hippuric acid. Tuberculin and mallein tests. Treatment, as in leukæmia. Excision in cases not constitutional. Phosphorus, phosphide of zinc.

Definition. Hypertrophy of the lymphatic glands with little or no leucocytosis. There may further be lymphoid growths in the liver, spleen, bone marrow and other organs.

The visceral lesions in lymphadenoma do not differ in character from those of leukæmia, and as it does often apparently merge into that disease by the characteristic changes in the blood, it is denied by many that it constitutes a separate pathological entity. In his admirable monograph on leucæmia in the lower animals Nocard affirms their identity. The main excuse for keeping up an alleged distinction, is the frequent absence of leucocytosis, and this often supervenes after the lymphadenoma has existed for some time.

Causes. As in leucæmia, 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 lymphatic glands and this goes on to distinct lymphadenoma.

=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 leukæmia 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 trabeculæ or the cells; they are homogeneous throughout. The scraping of the cut surface 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.