A comparative study of lymphocytes in effusions of patients with tuberculosis or malignant disease.

The diagnostic value of the determination of the relative distribution of B (SmIg-positive) and T (E rosetting) cells in the blood and in pleural or ascitic effusions was evaluated in 10 patients with tuberculosis and in six with malignant diseases. A higher percentage of T and a lower percentage of B lymphocytes in serous fluids than in peripheral blood was observed for both groups of patients. We conclude that this procedure is valueless in differentiating between tuberculosis and malignant diseases when effusions containing predominantly lymphocytes and devoid of metastatic cells are examined.