Morphology of tumors induced in Hamsters by Simian adenoviruses

Subcutaneous hamster tumors induced by Simian adenovirus SA7, strains C8, B105 and C626, were found to be poorly differentiated sarcomas having morphological features which distinguish them from tumors induced at the same site by papovaviruses and the Rous sarcoma virus. In general, the adenovirus-induced tumors were morphologically alike, C8-induced sarcomas showing some differences. Tumors induced by this strain in the subcutaneous tissue, muscles, peritoneum and mediastinum were morphologically identical. Tumors found in the brain were mainly malignant ependymomas and choroid plexus carcinomas, generally originating in neuroectoderm. The oncogenicity of adenovirus SA7 (C8) in meso- and ectodermal cells has thus been demonstrated.