Usefulness and problems of cytological examination by endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis of mediastinal lymphadenopathy: A retrospective single-centre study

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive and useful technique for sampling mediastinal lymph nodes. High sensitivity and specificity of EBUS-TBNA in staging lung cancer have been reported. However, few studies have addressed the results of EBUS-TBNA in the diagnosis of mediastinal lymphadenopathy with or without lung cancer, since various neoplastic and non-neoplastic conditions can involve the mediastinal lymph nodes. The present study analysed the results of the cytological examination of mediastinal lymphadenopathy using EBUS-TBNA in Kansai Medical University Hospital (Hirakata, Japan). A total of 41 consecutive patients with mediastinal lymphadenopathy who underwent EBUS-TBNA between January 2008 and December 2019 in Kansai Medical University Hospital were enrolled. This cohort included 29 males and 12 females. Cytological analyses demonstrated that 16/17 (94.1%) patients with metastatic carcinoma were diagnosed as having carcinoma (malignancy). The sensitivity, specificity and positive predictive value of the cytological examination in cases of carcinoma were 94.1, 100 and 100, respectively. However, only 3/11 (27.3%) patients with sarcoidosis were diagnosed by cytological examination. The present study demonstrated that EBUS-TBNA may be a useful method for detecting metastatic carcinoma in the mediastinal lymph nodes. However, the detection rate of epithelioid granuloma, which is a characteristic feature of sarcoidosis, was low in the present cohort. Hence, an improvement in the sampling technique is necessary.