An experimental osteosarcoma of the athymic nude rat.

In this report we describe an experimental osteogenic sarcoma that had been radiation-induced on Sprague-Dawleys by Delbrück in 1980. We transplanted it to 120 athymic nude rats achieving take rates of 100%. The tumor doubling time was 10.5 days. The osteosarcoma on athymic rats thus proliferated extraordinarily well compared to other known models. Pulmonary metastases were demonstrated in 100% of the examined animals. Pathological examinations revealed morphological similarities to human osteosarcoma and no signs of anaplasia.