What is the key question?

• Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is now the accepted technique for diagnosis and staging of mediastinal lymph nodes in lung cancer. Cryobiopsy is a relatively novel method which has been shown to yield larger samples in transbronchial and other biopsy specimens.

What is the bottom line?

• This study examined the diagnostic yield and safety of transbronchial mediastinal cryobiopsy using endosonography for the diagnosis of mediastinal lesions. In a group of patients with lesions greater than 1cm in diameter, fine needle aspiration (FNA/TBNA) and cryobiopsy were performed in randomised order. Of 197 patients enrolled, the overall diagnostic yield was 79.9% for FNA/TBNA and 91.8% for cryobiopsy (P=0.001). Sensitivity of cryobiopsy was superior to TBNA for uncommon tumour types (80.9% vs 53.2% for TBNA). There was no difference in procedural bleeding, pneumothorax or pneumomediastinum (although these events were rare) and there were no deaths attributable to either procedure. Cryobiopsy procedure was longer than TBNA (11.7 +- 5.3 min vs 9.4 +- 2.6 min), although for those familiar with these techniques, this difference is minimal in clinical practice.

Why read on?

• This trial shows the viability of mediastinal cryobiopsy for the diagnosis of benign and malignant diagnoses. There was a significant difference in diagnostic yield with no significant increased risk for adverse events in this study from two high volume centres. This is a promising technique that requires training and equipment that may not be available in all centres and further studies are required to better define the risk:benefit in “real world” situations.