The Role of Convex Probe Endobronchial Ultrasound Guided Transbronchial Needle Aspiration in the Diagnosis of Malignant Mediastinal and Hilar Lymph Nodes

Background: in the diagnosis of malignant lymph nodes (lns) and staging of lung cancer, sampling of mediastinal and hilar lns is essential. mediastinoscopy is known as the gold standard. convex probe (cp) endobronchial ultrasound (ebus)-guided transbronchial needle aspiration (tbna) is a noninvasive and highly sensitive diagnostic method in mediastinal and hilar ln sampling. objectives: evaluating the role of cp-ebus-guided tbna in the diagnosis of mediastinal and hilar lns suspicious of malignancy. patients and methods: one hundred twenty patients with a known lung malignancy or hilar/mediastinal lns detected by thoracic computed tomography (ct) and/or positron emission tomography (pet)-ct suspicious for malignancy were included in this prospective study. the procedure was performed by olympus 7.5 mhz cp endoscope and eu c2000 processor by the oral route under topical anesthesia and conscious sedation. after visualization of lns, their dimensions were recorded. aspiration was considered as “insufficient” if there were inadequate lymphocytes on the smears. diagnosis of “malignancy” on cytologic examination was considered as the “final diagnosis”. if diagnosis was negative for malignancy, more invasive procedures were performed to confirm the diagnosis. results: twenty four females and 96 male patients (mean age, 57.8 ± 9.1) were included. a total of 177 ln stations were aspirated in 120 patients. in 82 patients, the diagnosis was malignant by ebus-guided tbna and in the remaining 38; the diagnosis was established by further invasive procedures. of the 38 ebus-guided tbna negative patients, 28 were diagnosed as non-malignant and 10 were malignant. the sensitivity, diagnostic accuracy and negative predictive value of cp ebus-guided tbna were 89.1%, 91.6% and 73.6%, respectively. no major complications were seen. conclusion: as an alternative method to mediastinoscopy, ebus-guided tbna is a safe and noninvasive procedure with high sensitivity in the diagnosis of malignant mediastinal lns.