Tumors Induced in the South American Marmoset Monkey by Rous Sarcoma Virus

Summary

Metastasizing neoplastic growth was induced in newborn and adult South American marmoset monkeys by the Carr-Zilber and Schmidt-Ruppin strains of the Rous sarcoma virus. Two of eight adult cotton-top marmosets [Saguinus (Oedipomidas) oedipus] inoculated intramuscularly with the Carr-Zilber strain developed slowly growing fibrosarcomas and spindle cell sarcomas. Eleven of twelve adult cottontop marmosets and white-lipped tamarin marmosets (S. nigricollis group) inoculated intramuscularly with the Schmidt-Ruppin strain developed rapidly growing round cell and spindle cell sarcomas, frequently with multinucleated giant cells. These tumors frequently became very large and metastasized regularly to lymph nodes but infrequently to the lungs. Death from Schmidt-Ruppininduced tumor in adults usually occurred in 6–8 weeks. In newborn animals inoculated with this strain, the latent period was as short as 25 days before the development of invasive and metastatic spindle and round cell sarcomas, and terminal stages were reached in 3–6 weeks. Two adult marmosets developed sarcomas after inoculation with a cell-free filtrate of the Schmidt-Ruppin strain. Spontaneous neoplasms were not observed in the marmoset colony over a 4½-vear period.