Primary cardiac tumors are extremely rare. Obtaining a tissue diagnosis is difficult and commonly requires open-heart surgery with associated morbidity. Esophageal endoscopic ultrasound (EUS) and EUS with the EBUS scope (EUS-B) provide real-time sampling of centrally located lung tumors and mediastinal lymph nodes. They also provide an excellent view of the left atrium, since it is located adjacent to the esophagus. To date, left atrium tumor diagnostics by endosonography is poorly explored. We describe 2 exceptional diagnostic cases of left atrium tumors in which cardiac surgery was hazardous due to the clinical condition or previous surgical interventions. During EUS-B-guided fine-needle aspiration (FNA), the left atrial masses were successfully and safely sampled, revealing a Burkitt lymphoma and a synovial sarcoma. FNA including cell block analysis enabled specific tumor diagnosis and molecular subtyping. Our findings suggest that in selected cases, linear endosonography qualifies as a minimally invasive technique for intracardiac tumor diagnostics.
© 2021 The Author(s). Published by S. Karger AG, Basel.

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