The inflammatory response to a foreign body within transplantable tumors.

Several transplantaDitmouse and rat tumors were injured in a reproducible manner by implanting a length of cotton thread in their substance. Normal tissues, including liver, spleen, kidney, and subcutaneous connective tissue, were treated similarly. At the end of 1 week tissues containing thread were removed for histologie study. Consistent ly, the inflammatory response to the foreign body within the neoplasms was minimal as compared with the normal tissues. Although the tumors varied considerably in archi tecture and origin, differences in inflammatory response among the tumor types were not evident. A rapidly growing nonmalignant tissue, regenerating liver after partial hepatectomy, responded like the normal tissues after 7 days' exposure to the thread.