Lung Tumors Produced by Intratracheal Inoculation of Polyoma Virus in Syrian Hamsters

Proliferative lesions of bronchiolar and alveolar-lining cells, and tumors with histologic features of bronchiolar carcinoma, alveolar-cell carcinoma, and squamous-cell carcinoma have been produced in the lungs of hamsters inoculated intratracheally with polyoma virus. The areas of squamous-cell carcinoma appeared to arise in bronchioles and intrapulmonary bronchi; however, no evidence of origin from trachea or main bronchi was found. A transplantable squamous-cell carcinoma has been derived from one of the lung tumors and has retained squamous differentiation for four transplant generations. Attempts to isolate polyoma virus from one of the lung tumors and from the transplanted squamous-cell carcinoma have been unsuccessful. The possible significance of these findings in the search for etiologic factors in human lung cancer is discussed.