Impacting factors of diagnostic accuracy of ultrasound-guided percutaneous core needle biopsy in mediastinal lesions: an analysis with 622 cases.

Background: Ultrasound-guided percutaneous core needle biopsy (UGNB) has been widely adopted in pre-treatment pathological diagnosis in mediastinal neoplasms, while the accuracy rates varied in previous reports. We analyzed the impacting factors of accuracy in this retrospective study, aiming to further improve the diagnostic yield. Methods: Patients with mediastinal lesions who had undergone UGNB in Shanghai Chest Hospital between August 2013 and September 2022 were included in this study. All relevant medical information was retrieved from the database of our institution. The accuracy of biopsy was verified by post-surgery pathology or clinical outcome after long-term follow-up. Potential impacting factors, such as gender, age, tumor size, cystic necrosis, needle gauge and vascularity, were analyzed via binary logistic regression. Results: A total of 622 patients were enrolled in this study. There were 366 males and 256 females with an average age of 45 years old. There were 585 (94.05%) patients who obtained a successful diagnosis after biopsy, with a complication (≥ grade 2) rate of 3.86%. Thymic epithelial tumor (n=295), lymphoma (n=190) and germ cell tumor (n=51) were the most common three types. Cystic necrosis and younger age (<40 years) were tested to be significant impacting factors that lead to unsuccessful diagnosis, with P=0.001 and P=0.02, respectively. Conclusions: UGNB is an effective diagnostic approach for patients with mediastinal tumors with minor complications. Cystic necrosis and younger age were significant impacting factors for unsuccessful diagnosis. New techniques, such as contrast-enhanced ultrasound and rotational core needle, may probably increase diagnostic accuracy and reduce complications.