B cell chronic lymphocytic leukemia and lung carcinoma with T-lymphocyte-rich pleural effusion in a single patient

The case of a patient with B cell chronic lymphocytic leukemia (CLL) and T-lymphocyte-rich pleural effusion secondary to carcinoma of the lung is presented. Monoclonal B cells were the main cell population in the peripheral blood and the helper/suppressor cell ratio of the residual T lymphocytes was lower than 1. On the contrary, T lymphocytes with helper phenotype were prevalent in the pleural fluid. The results indicate that local factors influence strongly the distribution of the lymphocyte subpopulations in different districts of the body and suggest that an etiopathogenesis unrelated to the B cell lymphoproliferative disease must be searched for, when a T-cell-rich pleural effusion is present.