SMARCA4-Deficient Undifferentiated Tumor Achieved by Transbronchial Mediastinal Cryobiopsy Additional to Needle Aspiration.

Lung cancer is the leading cause of deaths from malignant neoplasms worldwide, and a satisfactory biopsy that allows for histological and other analyses is critical for its diagnosis. Guidelines have recommended endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) as the reference standard for the staging of lung cancer. However, the relatively limited sample volume retrieved by needle aspiration might restrict the diagnostic capacity of EBUS-TBNA in other uncommon thoracic tumors. Transbronchial mediastinal cryobiopsy is a recently developed sampling strategy for mediastinal lesions, which demonstrates added diagnostic value to conventional needle aspiration. Here, we present a case of thoracic SMARCA4-deficient undifferentiated tumor successfully diagnosed by mediastinal cryobiopsy additional to EBUS-TBNA.