CT-guided percutaneous transthoracic biopsy in the diagnosis of mediastinal masses: evaluation of 73 procedures

Purpose. This study was performed to evaluate the factors affecting the diagnostic accuracy and rate of complications of CT-guided percutaneous transthoracic needle biopsy of mediastinal masses. Materials and methods. We reviewed 73 consecutive mediastinal biopsies in 70 patients. Final diagnoses were based on a retrospective analysis of surgical outcomes, results of repeat biopsies or findings of imaging and clinical follow-up lasting at least 4 months. Benign and malignant biopsy findings were compared with the final outcomes to determine the diagnostic accuracy of the method. Finally, we analysed the complications. Results. CT-guided percutaneous transthoracic needle biopsy provided adequate samples in 61/73 cases, with a total sample rate of 83.6%. Of these 61 biopsies, 51 yielded a correct diagnosis with specific histological typing, mainly in the case of thymoma and metastasis. Lymphomas were less reliably diagnosed. The overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy values were 83.6%, 100%, 100%, 35.3% and 83.6%, respectively. Pneumothorax was the most common complication (5.5%). Conclusions. CT-guided percutaneous transthoracic needle biopsy is an easy, reliable and safe procedure that obviates the need for exploratory surgery in medically treatable or unresectable cases. It should be the first invasive procedure in the diagnostic workup of mediastinal masses.