Thymus function in patients with resectable lung carcinoma.

A series of 43 patients (median age 57 years, range 39-73) underwent biopsy of the thymic area during resection for primary lung cancer (16 with negative nodes and 27 with positive nodes). In 22 cases in which study of lymphocyte subpopulations was possible T6 precursor thymocytes were found (mean 57%). T4 and T8 cells were present in proportions of 53% and 47%, respectively, equally distributed between T6 and T3 cells. A well-defined lobular structure was found in 11 cases and active thymic tissue with poorly defined lobules in 21 cases. There was no correlation of active thymus tissue either with age or with lymph node status. It is hypothesized that thymic tissue undergoes regeneration in response to tumor development, 50% of thymocytes being of the suppressor type in early tumors. Thymic structure in advanced cancer has not yet been studied.