Abstract
BACKGROUND: Intimal sarcoma (IS) is a rare malignant tumor originating from the tunica intima of large blood vessels, mainly in the pulmonary circulation. Prevalence is extremely low (0.001%), with IS of the pulmonary vein even rarer than IS of the pulmonary artery (0.001%-0.003%). CASE SUMMARY: A 73-year-old man with malignant peripheral nerve sheath tumor and high-grade urothelial carcinoma was diagnosed with grade 3 pulmonary vein IS during evaluation of probable acute decompensated heart failure. Echocardiography showed a hyperechoic mass extending from the pulmonary vein into the left atrium and protruding into the left ventricle. The patient underwent surgical resection. DISCUSSION: Despite invasive interventions, aggressive IS often recurs, making regular imaging follow-up essential for early detection of metastasis and highlighting the need for further research into effective treatment strategies. TAKE-HOME MESSAGE: This case highlights the importance of including pulmonary vein IS in the differential diagnosis of left atrial masses and the value of multimodality imaging for timely detection and surgical planning.