Intracardiac Extension of Testicular Germ Cell Tumor via the Left Superior Pulmonary Vein Mimicking Thrombus.

backgroundTesticular germ cell tumors (TGCTs) are the most common malignancies in adolescent and young adult men, and they can spread to multiple organs in patients with advanced disease. The lungs are the most common site of metastasis in testicular cancer, and they may invade the left atrium either by direct extension or via the pulmonary veins. CASE PRESENTATION: A 42-year-old man presented with progressive dyspnea and typical anginal chest pain. The patient was diagnosed with TGCTs 4 years ago, refractory to chemotherapy, with metastases to multiple organs including the lungs and brain. Transthoracic echocardiography revealed a prominent left atrial mass, initially misinterpreted as a thrombus. Imaging and surgical findings revealed the mass to be an extension from the pulmonary vein originating from a TGCT. DISCUSSION: Cardiac metastases are more common from lung tumors owing to their close proximity to the heart, emphasizing the need for advanced imaging modalities for timely and accurate detection. TAKE-HOME MESSAGE: TGCTs may in rare cases metastasize to the heart through a nonhematogenous route via the pulmonary veins, highlighting the necessity of accurate diagnosis through multimodality imaging.