The regional lymph node in cancer. Relationship of nodal histologic findings to cytotoxicity and immunity.

Although regional lymph nodes showed increased numbers of pyroninophilic cells for at least six weeks after the implantation of a C3H mammary tumor, a decrease in the number of these cells was noted four weeks after amputation of a tumor-bearing limb. These observations appear paradoxical, since such animals have repeatedly demonstrated so-called sinecomitant tumor immunity. However, the lack of pyroninophilia coincided with prior observations that cells obtained from the regional nodes after amputation of a tumor-bearing limb-showed decreased in vitro cytotoxicity. This suggested that the pyroninophilic elements, vis a vis immunoblasts, may have been more closely related to cytotoxicity rather than to tumor immunity per se. The possible importance of nodal lymph follicle formation in the latter was suggested by their increased presence in such regional nodes.