Endobronchial ultrasound-guided transbronchial needle biopsy for the diagnosis of mediastinal lymphadenopathy in patients with extrathoracic malignancies

Turkish Journal of Medical Sciences Turk J Med Sci (2014) 44: 989-995 © TÜBİTAK doi:10.3906/sag-1309-127 http://journals.tubitak.gov.tr/medical/ Research Article Endobronchial ultrasound-guided transbronchial needle biopsy for the diagnosis of mediastinal lymphadenopathy in patients with extrathoracic malignancies 1, 1 1 1 2 Ayşegül ŞENTÜRK *, Hatice KILIÇ , Habibe HEZER , Funda KARADUMAN YALÇIN , Hatice Canan HASANOĞLU 1 Department of Pulmonary Disease, Atatürk Training and Research Hospital, Ankara, Turkey 2 Department of Pulmonary Disease, Faculty of Medicine, Yıldırım Beyazıt University, Ankara, Turkey Received: 30.09.2013 Accepted: 03.01.2014 Published Online: 24.10.2014 Printed: 21.11.2014 Background/aim: Mediastinal lymphadenopathy is common in extrathoracic malignancies and should not always be considered a metastatic lesion. The purpose of this study is to determine the diagnostic value of endobronchial ultrasound-guided transbronchial needle biopsy (EBUS-TBNA) in patients with extrathoracic malignancies. Materials and methods: This study included 54 consecutive patients with extrathoracic malignancies who had suspected mediastinal metastases and had undergone EBUS-TBNA for diagnosis. Results: Using EBUS-TBNA, 27 of 54 patients (50%) were diagnosed with mediastinal metastases. Among patients with mediastinal metastases, 2 (3.7%) had a sarcoid-like reaction, 5 (9.3%) had tuberculosis, and 17 (31.5%) had reactive lymph nodes. In 3 cases (5.5%), a specific diagnosis could not be determined following EBUS-TBNA. Two patients underwent surgical staging of their mediastinal lymphadenopathy, which allowed the detection of mediastinal metastases in 1 patient and that of reactive lymph nodes in the other. The sensitivity, specificity, negative predictive value, and diagnostic accuracy of EBUS-TBNA for the diagnosis of extrathoracic malignancies were calculated as 93%, 100%, 92.6%, and 96.3%, respectively. Conclusion: EBUS-TBNA is a safe and effective procedure. We should consider whether EBUS-TBNA should be the primary diagnostic tool for the diagnosis of mediastinal lymphadenopathy in patients with extrathoracic malignancies. Key words: EBUS-TBNA, extrathoracic malignancies, mediastinal lymphadenopathy 1. Introduction Enlarged mediastinal lymph nodes can occur in both intrathoracic and extrathoracic malignancy cases. This frequently poses a diagnostic challenge for respiratory physicians and oncologists. Intrapulmonary metastatic lesions spread through the vascular system and then form lymph node metastases by lymphatic spread (1). Mediastinal lymphadenopathy that is detected during follow-up visits for patients with extrathoracic malignancies should not always be considered a metastatic lesion. Instead, it could be a simultaneous primary lung malignancy or granulomatous disease. Determining the etiology of lymph node status is important for making decisions about therapeutic management and for determining prognosis (2). Breast carcinoma, colorectal carcinoma, renal cell carcinoma, and melanoma are all prone to spreading to the chest. Computed tomography (CT) scans are commonly used to diagnose lung metastases. Identification of lymph node metastasis is more problematic since a metastasis * Correspondence: with an upper size limit of 4 mm may result in a false negative rate of approximately 10% by CT (3). Positron emission tomography (PET)-CT images display signs that can help the physician to differentiate between benign and malignant disease, making this an important method for the evaluation of mediastinal lymphadenopathy. However, inflammatory reactions of lymph nodes may lead to the accumulation of fluorodeoxyglucose (FDG), resulting in a 10% false positive rate. False positive PET results may confuse clinicians; therefore, histopathological confirmation is required (4). For many years, mediastinoscopy has been the most commonly used technique for sampling intrathoracic lymphadenopathy. However, it only has limited usefulness for the evaluation of the aorticopulmonary window and the posterior subcarinal and hilar regions. Furthermore, mediastinoscopy requires general anesthesia, and patients receiving chemotherapy may be reluctant to undergo this invasive procedure (5,6). Endobronchial ultrasound (EBUS), which only requires conscious sedation, is a more easily applicable technique 989 ŞENTÜRK et al. / Turk J Med Sci and is less expensive than mediastinoscopy. Moreover, EBUS allows sampling from the posterior subcarinal and hilar regions. For these reasons, over the last few years clinicians have been implementing EBUS for the evaluation of mediastinal lymph nodes. EBUS with real-time guided transbronchial fineneedle aspiration (TBNA) is currently used as a reliable diagnostic tool for enlarged lymph nodes in patients with malignancies, as well as for the evaluation of suspected benign granulomatous diseases. Studies show that this method has high specificity and accuracy but low negative predictive value (NPV) and sensitivity, which necessitates a confirmatory technique in the case of a nonmalignant result from EBUS-TBNA of a suspicious mediastinal lymph node (7). The aim of this study is to determine the diagnostic value of EBUS-TBNA for mediastinal lymphadenopathy in patients with extrathoracic malignancies. The accurate diagnosis of lymph node metastasis is very important for deciding which treatment modality is chosen. Therefore, EBUS-TBNA should be applied in order to assess lymph node metastasis before mediastinoscopy. 2. Materials and methods Fifty-four consecutive patients, who were suspected to have intrathoracic lymph node metastasis resulting from extrathoracic malignancies between 2010 and 2012 and who had undergone EBUS-TBNA, were retrospectively reviewed (7.5 MHz, BF-UC160F; Olympus Optical Co., Tokyo, Japan). Written informed consent was obtained from all patients and the study was approved by the local institutional ethics committee. All EBUS-TBNA procedures were performed under moderate sedation with intravenous midazolam alone, or midazolam plus fentanyl, by the same interventional pulmonologist. Patients were suspected to have intrathoracic lymph node metastases based on enlargement (short axis of >10 mm) visualized by CT or FDG uptake of ≥SUV 2.5 on PET scans (Figure 1). Before EBUS-TBNA, a pulmonologist used flexible bronchoscopy to examine each patient. No endobronchial mucosal abnormalities were found. EBUS-TBNA was subsequently used to examine all accessible lymph nodes. At least 3 passes were performed in each lymph node (Figure 2). A portion of the needle sample was spread on glass slides and dried at room temperature for Ehrlich–Ziehl–Neelsen staining and cytological examination. Another sample portion was placed in a mixture of alcohol and formaldehyde. Separate samples were also put in formaldehyde to form cell blocks and were cultured in Löwenstein–Jensen medium. The remaining material was put in a saline solution (...truncated)