Papillary Ependymomas Produced in Rattus (Masfomys) Natalensis inoculated With Vacuolating Virus (SV40)

Subcutaneous inoculation of newborn Mastomys with simian vacuolating virus (SV40) has resulted in production of brain tumors with histopathologic characteristics of papillary ependymomas. The tumors have been found in 8 of 10 animals that survived the inoculation trauma and have become evident after latent periods of 111 to 225 days. Although the oncogenic properties of preparations of SV40 have been previously demonstrated in Syrian hamsters, the present report indicates that the oncogenic activity is not limited to the Syrian hamster. The finding that subcutaneous inoculation of an oncogenic virus can produce brain tumors without subcutaneous or visceral tumors has not been previously reported. It suggests that some ependymomas in humans may result from subcutaneous inoculation of an oncogenic virus or a carcinogenic substance.