Studies on Transmissible Lymphadenosis of Mice. 20

Abstract

A new transmissible strain of malignant lymphadenosis isolated at the Henry Phipps Institute has been observed to possess the following properties.

It can be passed to mice of the stock in which it originated but not to other stocks. About 12% of mice of the same stock, and about half of the closely inbred relatives of the mouse from which this strain was derived were susceptible on intravenous inoculation, but the disease could not be transmitted to 2 unrelated stocks of mice.

The disease caused by intravenous inoculations of emulsions of lymph nodes and spleen resembles the spontaneous disease very closely. Both are characterized by a systemic enlargement of the lymph nodes and splenomegaly, associated with massive lymphoid infiltrations in organs such as bone marrow, liver, kidney, and ovary, assuming in the latter 2 organs tumor-like proportions. In spite of the intravenous route of injection and the massive infiltrations, the number of lymphocytes in the circulating blood was within normal limits or was only slightly increased. The percentage of lymphocytes was likewise within normal limits. Many cells seen in smears, however, were an unmistakable evidence of the disease process. These were medium or large lymphocytes with scant but intensely basophilic cytoplasm and hyperchromatic nuclei. A few cells contained, instead of nuclei, globular or angular material staining red with Romanowsky dyes, this being presumably the disintegrating nucleus. There were also, apparently intermediate between these and immature lymphocytes, lymphocytes with atypical chromatin structure.

Thus the new strain differs from the strains of transmissible lymphoid leucemia of mice previously described 1 in the morphological character of the lymphocytes involved.