Thymic lymphosarcoma in magnesium-deficient rats.

Dietary magnesium deficiency in rats for a minimum period of 40 days evokes typical cellular changes in the peripheral blood and the bone marrow; among survivors, 40% develop a thymic tumor. The growths were found irreversible in animals returned to a normal equilibrated diet. Histologic and ultrastructural studies indicated that we were dealing with a thymic lymphosarcoma. We noted the presence of virus-like particles in the cytoplasm of the tumor cells, but our investigations would favor the idea that these minute structures correspond to degradation products in an autophagic vacuole as part of the involute process of the neoplastic cells.