Transesophageal endoscopic ultrasound-guided aspiration of the left atrium for diagnosis of T-cell lymphoblastic leukemia/lymphoma: a case report

A 20-year-old woman was admitted due to progressive chest tightness. Positron emission tomography/computed tomography (PET/CT) showed diffuse metabolic hyperactivity in the heart and local mediastinum, which was considered suspicious for malignancy ([ Fig. 1 ]). To obtain a definitive pathological diagnosis, transesophageal endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) was planned. Examination of the mediastinum using a linear 7.5 MHz echoendoscope revealed the significant thickening of the left atrial wall ([ Fig. 2 ]). Subsequently, the left atrium was punctured under EUS guidance using a 19G needle ([ Fig. 3 ], [ Video 1 ]). No postoperative complications were observed. EUS-FNA pathological examination with HE staining confirmed lymphoma, with the following immunophenotypic markers ([ Fig. 4 ]): CD3 (positive), TdT (positive), and Ki-67 (positive, approximately 50% in hotspot areas). A final diagnosis of T-lymphoblastic leukemia/lymphoma(T-LBL/L) was established, providing a clear direction for subsequent treatments. Five months after chemotherapy, follow-up PET/CT showed significant improvement ([ Fig. 5 ]). The patient remains under an ongoing follow-up. Fig. 1 PET/CT showed diffuse metabolic hyperactivity in the heart and local mediastinum, which was considered suspicious for malignancy. PET/CT, positron emission tomography/computed tomography. Fig. 2 EUS demonstrated the left atrium and left ventricle, with the significant thickening of the left atrial wall. EUS, endoscopic ultrasound. Fig. 3 Puncture of the left atrium was performed under EUS guidance. EUS, endoscopic ultrasound. Download Video Puncture of the left atrium was performed under EUS guidance. EUS, endoscopic ultrasound.Video 1 Fig. 4 Histopathological and immunohistochemical finding diagnostics of T-lymphoblastic leukemia/lymphoma. a HE staining; b CD3 immunostaining (positive); c TdT immunostaining (positive); d Ki-67 immunostaining (positive, approximayely 50% in hotspot areas). Fig. 5 Five months after chemotherapy, the follow-up PET/CT showed significant improvement. PET/CT, positron emission tomography/computed tomography. T-LBL/L is a highly aggressive malignancy derived from immature precursor T-cells, characterized by extensive infiltration of immature T-cells into the peripheral blood, bone marrow, and/or extramedullary organs, with the frequent involvement of the central nervous system [ 1 ] [ 2 ]. However, myocardial infiltration is extremely rare. This case demonstrates that EUS-FNA can successfully obtain tissue samples from left atrial lesions, leading to a definitive diagnosis of T-LBL/L and providing critical guidance for clinical management and prognosis. Therefore, the potential value of EUS in non-gastrointestinal pathologies should not be overlooked [ 3 ]. Although EUS is currently less commonly applied in non-digestive fields, it still holds significant clinical value. Such cross-disciplinary exploration and application can deepen our understanding of EUS and offer clinicians additional diagnostic and therapeutic insights. Endoscopy_UCTN_Code_TTT_1AS_2AC Publication History Article published online: 26 February 2026 © 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/). Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany