Lymphocytic infiltration of bronchioloalveolar adenomas in mice

The proportion of mouse lung adenomas with associated lymphocytes was examined in relation to tumor histology, location within the lung, tumor invasiveness and surface lymphocyte markers. The highest proportion of lymphocyte positive tumors was found on the pleural surface in contact with lymphatics. Seventy eight percent of pleural Clara cell but only 16% of alveolar cell adenomas were positive for lymphocytes (P less than 0.001). The majority of tumor associated lymphocytes were Ig-positive, either IgG (53%) or IgA (45%). No correlation was found between lymphocytic infiltration and tumor invasiveness. Our data suggest that the affinity of lymphocytes for Clara cell adenomas may be determined by intrinsic differences between the two tumors rather than to biologic behavior.