Ultrasonic manifestations of intravascular leiomyomatosis involving the right atrium: a case report.

This case report describes a 37-year-old female with a history of cesarean section and uterine leiomyoma resection, who presented with recurrent dyspnea and palpitations. Echocardiography revealed a hyperechoic, mobile mass (3.9 × 2.2 cm) in the right atrium (RA) extending into the inferior vena cava (IVC), accompanied by global cardiomegaly, severe tricuspid regurgitation, and mildly reduced left ventricular function. Elevated tumor markers (CA125, CA199, CA50) and NT-proBNP were noted. Transvaginal ultrasound identified a large pelvic mass, while PET-CT demonstrated multiple pulmonary and pelvic lesions with mild FDG uptake, suggestive of benign intravascular leiomyomatosis with metastases. Pathological biopsy of pulmonary and pelvic lesions confirmed smooth muscle-derived tumors consistent with leiomyoma, supported by immunohistochemistry (SMA+, Desmin+, h-caldesmon+). This case highlights the characteristic ultrasonographic features and underscores the importance of a multidisciplinary diagnostic approach for intravascular leiomyomatosis involving cardiac structures.