Adenocarcinoma of the parotid gland in nude rats

Seven of approximately 200 rnu/rnu nude rats developed adenocarcinomas of the parotid gland. The malignant neoplasms ranged from well differentiated (grade 1) to poorly differentiated (grade 3) adenocarcinomas. The age of affected rats varied from 6 months to 1 year. The appearance of salivary gland adenocarcinomas in rnu/rnu rats is unusual and may have important implications for human tumor xenotransplantation in these animals.