Novel thin convex-probe endobronchial ultrasound bronchoscope-guided cryobiopsy for a peripheral pulmonary lesion.

[INTRODUCTION] The novel thin convex-probe endobronchial ultrasound (TCP-EBUS) bronchoscope could potentially expand the application of endobronchial ultrasound-guided cryobiopsy (EBUS-cryo), established for lymphadenopathy, to peripheral pulmonary lesions (PPLs). Herein, we report a case of EBUS-cryo using TCP-EBUS for a PPL that was difficult to access using conventional EBUS bronchoscopes.

[CASE PRESENTATION] Bronchoscopy was performed on an 80-year-old man with a history of laryngeal cancer to obtain a histological diagnosis of a PPL in the right lower lobe, to which a sixth-generation bronchus led. The lesion was visualized using TCP-EBUS, and EBUS-transbronchial needle aspiration (TBNA) was performed thrice; however, the specimen volume was limited. Subsequently, EBUS-cryo was performed twice through the TBNA puncture site, and a sufficient amount of specimen was collected. No severe complications were observed. The EBUS-TBNA specimens showed low tumor cellularity and crush artifacts, making definitive histological subtyping impossible. However, the EBUS-cryo specimens exhibited high tumor cellularity without crush artifacts or significant blood contamination. The morphological findings were different from those of previous laryngeal cancer specimens, supporting the diagnosis of primary pulmonary squamous cell carcinoma.

[CONCLUSION] TCP-EBUS may facilitate the use of EBUS-cryo for PPLs while maintaining safety, thereby addressing the limitations of EBUS-TBNA for tissue acquisition.