Background Endobronchial ultrasound (EBUS) guided transbronchial needle aspiration (TBNA) is an accurate outpatient procedure used to explore mediastinal lymph nodes for lung cancer staging and unexplained mediastinal masses.

Aims and methods A retrospective study was conducted over four years on EBUS-TBNA sampled lymph nodes investigated for the staging of lung cancer or unexplained mediastinal lymphadenopathies, first using the conventional method (CM) and then a liquid based cytology (LBC).

Results Of the 628 specimens (355 patients) collected, the overall rate of adequacy was 88% and the diagnosis of malignancy was achieved in 43% of cases. The inadequate rate was 6% with LBC and 21% with CM. A paraffin cytoblock was available in 80% with LBC and 62% with CM. Of the 628 aspirates, 270 (43%) were categorised as negative for malignancy including 26 cases consistent with sarcoidosis, 272 (43%) as malignant, 9 (1.4%) as suspicious for non-small-cell carcinoma and 77 as inadequate samples (12%). Of the 272 cases diagnosed as malignant, 87 (32%) were classified as non-small-cell carcinoma, 106 (39%) as adenocarcinoma, 48 (18%) as squamous cell carcinoma and 20 (7%) as small cell carcinoma. Five lymphomas, four metastatic melanomas and two carcinoids were also diagnosed.

Conclusions EBUS-TBNA is a reliable method for the staging of lung cancer and for unexplained mediastinal mass exploration. The LBC has a lower rate of inadequate samples, a better yield of cytoblock for immunohistochemistry and a dramatically reduced time requirement for interpretation as compared to CM.