On the occurrence of virus-like bodies in human leukemia.

By H. BRAUNSTEINER, K. FELLINGER AND F. PAKESCH D URING the last years, electron microscopic studies of leukemic tissues in chicken and mice have revealed the presence of intraand extracellularly located virus-like bodies.14 The bodies are very similar to those found in solid tumors of animals, such as Rous’ sarcomas or breast carcinomas.2’3 Some particles were also found in animals without evidence of leukemia or tumor. It might be expected that these results would intensify the search for viruslike particles in human leukemias. Positive results in single cases have been reported recently.4 Our research group has looked for evidence of viruses in human neoplastic conditions for about 10 years. One of us published a report with the Oberling group in Paris in 1950 in which the presence of virus-like bodies in spread leukemic cells was discussed.5 It was felt, however, that the method did not permit discrimination between virus-like bodies and microgranulations in leukemic cells. Since 1952, after the introduction of ultra-thin sectioning, these researches have been intensified and have become almost a routine procedure in our department. A rather extensive number of patients with acute or chronic leukemia, Hodgkins’ disease, myeloma and lymphosarcoma were examined. In a previous study published in this journal the cytologic features were described.6 The present study gives a short quantitative survey of our work in relation to “positive findings of virus-like bodies.” It is believed that the quantitative aspect must be discussed before such findings can be interpreted.