FIG. 86.—Blood: Lymphatic leukemia (lower section); marked leukocytosis (upper section). Stained smears. Compare types of leukocytes with Fig. 85 (from Greene's "Medical Diagnosis").

2. Lymphatic Leukemia.—This form may be either acute or chronic. There is marked loss of hemoglobin and red corpuscles. The color-index is usually moderately low.

The leukocyte count is high, but lower than in the myelogenous type. Counts of 100,000 are about the average, but in many cases are much lower. This high count is referable almost wholly to increase of lymphocytes. They generally exceed 90 per cent. of the total number. In chronic cases they are chiefly of the small variety; in acute cases, of the large form. Myelocytes are rare.

The red corpuscles show the changes usual in severe secondary anemia. Erythroblasts are seldom abundant. Blood-plaques are decreased.

3. Pseudoleukemia (Hodgkin's disease) resembles lymphatic leukemia in that there is marked and progressive enlargement of the lymph-nodes. There is, however, no distinctive blood-picture. The changes in hemoglobin and red cells resemble those of a moderate symptomatic anemia, with rather low color-index. The leukocytes are commonly normal in number and relative proportions.

4. Anæmia Infantum Pseudoleukæmica.—Under this name von Jaksch described a rare disease of infancy, the proper classification of which is uncertain. There is enlargement of liver and spleen, and sometimes of lymph-nodes, together with the following blood-changes: grave anemia with deformed and degenerated red cells and many erythroblasts of both normoblastic and megaloblastic types; great increase in number of leukocytes (20,000 to 100,000), and great variations in size, shape, and staining of leukocytes, with many atypical forms and a few myelocytes.

The table on the following page contrasts the distinctive blood-changes in the more common conditions.

DIFFERENTIAL DIAGNOSIS OF BLOOD DISEASES
SECONDARY ANEMIA. PERNICIOUS ANEMIA. CHLOROSIS. MYELOGENOUS LEUKEMIA. LYMPHATIC LEUKEMIA.
Hemoglobin. Diminished according to degree of anemia. Diminished. Greatly diminished. Decidedly diminished. Markedly diminished.
Red Corpuscle Count. Normal in mild cases; diminished in all others. Greatly diminished. Slightly diminished. Decidedly diminished. Markedly diminished.
Color-index. Normal or slightly diminished. High. Low. Usually slightly diminished. Usually slightly diminished.
Leukocyte Count. Not necessarily affected; leukocytosis common. Normal or diminished. Normal or diminished. Extremely high. Very high.
Red Corpuscles on Stained Films. Variations in size and shape in moderate cases; variations in staining reactions and normoblasts in severe cases. Marked variations in size, shape, and staining reactions. Average size increased. Tendency to large oval forms. Erythroblasts always present; megaloblasts exceed normoblasts. Nearly uniform size and shape; average size decreased; pale centers. Erythroblasts very rare. Similar to secondary anemia, except normoblasts generally very numerous. Similar to secondary anemia. Erythroblasts not numerous.
Leukocytes on Stained Films. Normal proportions or increase of polynuclears. Lymphocytes relatively, sometimes absolutely, increased. Lymphocytes apt to be relatively increased. Large numbers of myelocytes (average, 20 per cent.). Absolute increase of eosinophiles and basophiles. Relative decrease of polynuclears and lymphocytes. Lymphocytes exceed 90 per cent. Other varieties relatively decreased.