Mediastinal cyst infection followed by bacteremia due to Streptococcus anginosus after endobronchial ultrasound-guided transbronchial needle aspiration.

We herein report a case of recurrent mediastinal cyst infection followed by bacteremia after endobronchial ultrasound-guide transbronchial needle aspiration (EBUS-TBNA). A 65-year-old Japanese male with sarcoidosis presented with 4 L progressive lymph node adenopathy and was diagnosed with mediastinal cyst by EBUS-TBNA. After bronchoscopy, he suffered from a high fever. Chest computed tomography showed enlargement of the 4 L lymph node with low attenuation areas, the elevation of mediastinal fat concentration. Blood cultures were positive for Streptococcus anginosus. Antimicrobial agents were administered for a total of 12 weeks, at which point the size of the lymph node was reduced. However, at 5 months after the discontinuation of antimicrobial agents, the mediastinal cyst infection recurred. It is important to conduct careful follow-up because mediastinal cyst infection following ebus-tbna may relapse with conservative treatment without invasive surgery.