Leukemic Lymphoblastoma in a Calf: A Hematologic and Histologic Study

Abstract

The pathology of diseases involving the lymphoid organs of human beings and of the lower animals is much confused. The excellent reviews of the subject of “leukosis” in cattle and calves by Jarmai (1) and by Dobberstein and Paarmann (2) have impressed us with the need for a comprehensive study of the histogenesis of the morbid process. In the present study, therefore, an attempt has been made to follow the histogenesis of the changes in the lymphoid tissues of a calf with leukemic lymphoblastoma and to correlate these changes with those in the peripheral blood. Material and Methods A calf about three months of age with generalized lymphadenopathy was obtained from a public stockyard. The blood was found to contain 24,000 leukocytes per cubic millimeter, 68 per cent of which were immature lymphocytes. Subsequent daily examinations of the blood included a determination of the number of leukocytes and erythrocytes per cubic millimeter and of the value for hemoglobin. The number of leukocytes and erythrocytes was determined with standard pipets; values for hemoglobin were determined by the Sanford-Sheard photo-electric hemoglobinometer, and the blood smears for the differential counts were prepared with the May-Grunwald-Giemsa stain. To correlate the changes in the lymphatic tissue with those of the peripheral blood, three biopsies were performed on enlarged superficial lymph nodes; imprint preparations were made of the unfixed cut surfaces of the tissues, and these were stained with the May-Grunwald-Giemsa stain. These stained preparations were studied with the same technic as was used for blood smears.