Normal Splenic Tissue Research Articles

A Transferable Liver Neoplasm (C198) Arising in a Female Mouse of the Leaden Strain

An old breeding female mouse from the leaden stock, killed in March 1936, showed at autopsy a considerable enlargement of the liver and spleen. In the spleen were several large grayish-white bulging nodules. The liver appeared edematous with several blood-filled cysts scattered over the surface. Although this was an internal tumor, the tissue fragments were implanted subcutaneously in the right axillary region, in other leaden mice. Weekly observations were made to determine and record any palpable tissue changes at the site of implantation. In some animals small soft masses were detectable for a short time, but these soon disappeared and the mice were considered negative. At seven weeks, however, abdominal enlargement began to appear and several animals died suddenly. At autopsy the sudden deaths were seen to be due to internal hemorrhages from ruptured blood-filled cysts at the surface of the liver. All the animals showed enlarged livers and in some the spleen was involved. These changes were grossly similar to those seen in the female from which the inoculated tissue was taken. The sections of the primary tumor (C198) in the liver showed the cords of parenchyma cells distorted and somewhat compressed by masses of rounded and spindle-shaped cells which engorged the hepatic sinusoids. These cells showed occasional mitoses and appeared to originate from the reticular endothelium (Fig. 1). They surrounded the blood vessels and partially or totally occluded their lumina. Similar cells were found in the spleen (Fig. 2), where they formed large and small cell nests which replaced the normal splenic tissue and occluded the blood vessels. This condition developed rather rapidly and resulted in the death of the inoculated animals. In the positive animals the livers were always involved and frequently the lungs and spleen showed tumor lesions. The liver changes occurred regardless of the presence or absence of a palpable mass at the site of injection.