BackgroundThe study evaluated the safety and adequacy of percutaneous transsternal anterior mediastinal core biopsy. MethodsAll percutaneous computed tomography–guided transsternal mediastinal 18-gauge core biopsies performed at 2 academic centers were retrospectively reviewed. Procedural, clinical, and pathology data were recorded. ResultsSixteen patients underwent biopsies. Nine had preexisting cancer diagnoses. Biopsy was performed with general anesthesia (3), monitored anesthesia care (7), and moderate sedation (6). All patients were discharged the same day, except 1 patient, in whom a pneumothorax developed, necessitating chest tube placement. Of 16 biopsies, 15 (94%) yielded pathologic diagnoses, including thymoma (4), benign lesion (3), and 8 malignant neoplasms (3 lung cancer, 3 lymphoma, 1 thymic carcinoid tumor, 1 sarcoma). In most (14/16), ≥3 core specimens were obtained. In the nondiagnostic biopsy, only 1 core was obtained. Tissue was adequate in 4 of 6 cases for ancillary testing. Eight patients received diagnoses from core biopsy indicating observation or medical therapy, obviating the need for surgery. ConclusionsOutpatient transsternal anterior mediastinal 18-gauge core biopsy is feasible, safe, and effective and may prevent unnecessary surgeries. Obtaining ≥3 cores may optimize diagnostic yield.