Search strategy and initial review
The authors performed a systematic search of the two databases: PubMed and EMBASE (2004–2017) to identify the relevant studies on EBUS-TBNA/EUS-B-FNA in children (<18 years). The following free text search terms were used: (ebus OR ebus-tbna OR ebus tbna OR tbna OR endobronchial ultrasound OR endobronchial Ultrasonography OR endobronchial ultrasound-guided OR endobronchial ultrasound-guided OR tbna OR eus b fna) AND (pediatric OR pediatric OR child OR children). The authors also reviewed their personal files to identify relevant studies. All the retrieved references were imported into reference management software (EndNote). Duplicate references were removed. References were screened through the title and abstracts. The reference lists of the extracted studies were reviewed. The finally retrieved studies were independently screened by two authors (HI and KM). Full texts of the relevant articles were obtained. The following types of studies were excluded – (a) studies that did not report the utilization of either EBUS-TBNA/EUS-B-FNA or were not related to paediatrics (b) studies describing the use of conventional TBNA for mediastinal lesions in children (c) studies not in the English language (d) review articles, editorials and letters without any case description. Any disagreement between the authors was resolved after mutual discussion. The systematic review methodology is summarized in Figure 1.