Significance of the presence of lymphocytes in the cytological analysis of transbronchial needle aspiration

To evaluate the clinical relevance of the presence of lymphocytes in transbronchial needle aspiration (TBNA) samples from pathological mediastinal lymph nodes in patients with suspected lung cancer. Retrospective observational study evaluating the negative predictive value (NPV) of TBNA samples containing lymphocytes but not malignant cells. A total of 266 TBNA were performed in 252 patients with pathological lymph nodes. One hundred and fifteen TBNA samples had evidence of malignant cells (43%), and 94 (35%) samples were considered as inadequate (absence of adequate cytological material or exclusive presence of bronchial epithelial cells). Out of the 57 TBNA samples remaining (21%), 15 could not be confirmed; in 32, TBNA samples were confirmed with alternative diagnostic techniques and in 10, they were confirmed after clinical and radiological follow-up. The NPV of the 32 samples that were confirmed with alternative diagnostic techniques was 84% decreasing down to 76% when the 10 TBNA samples confirmed after clinical and radiological follow-up were included. The presence of lymphocytes in the TBNA sample does not exclude the neoplasic invasion of the specific lymph node analyzed.