Damage to the Thymus and Other Lymphoid Tissues from 3-methylcholanthrene, and Subsequent Thymoma Production, in Mice.

Serious damage in lymphoid tissues was seen on post-mortem examination of CF1 Swiss and C57BL mice subjected to intraperitoneal injection of 3-methylcholanthrene (MC) between 12 hours and 9 days after birth. In life such mice exhibited an acute or chronic wasting syndrome clinically and histologically similar to runting syndromes occurring after immunological procedures, but presumably different in origin. Thymomas were produced in many of the CF1 Swiss mice surviving more than 2 months after MC injection, but not in any C57BL mice. Lung adenomas and some other tumors were produced in other CF1 mice between 5 and 8 months after treat ment.