Inferior Vena Cava Masson's Tumor Extending Into the Right Atrium and Ventricle: A Case Report

Intravascular papillary endothelial hyperplasia (IPEH) is an uncommon vascular lesion, typically found on the skin of the head, neck, and extremities. Angiosarcoma remains the most important differential diagnosis and should be excluded based on histopathologic features. The preferred treatment for IPEH is complete surgical excision, as incomplete resection may lead to recurrence. We report the case of a 46-year-old female who was evaluated for chest pain and syncope, revealing a right-sided cardiac mass. There was uncertainty regarding the origin and full extent of the cardiac mass despite transthoracic and transesophageal echocardiography. Transesophageal echocardiography localized the lesion to the inferior vena cava (IVC), while open-heart surgery confirmed its full 14 cm extent and IVC origin. The mass was completely excised, and histopathology was consistent with IPEH (Masson's tumor). This case presents a rare vascular tumor at an unusual location, which initially posed a diagnostic challenge. However, through a collaborative approach with a multidisciplinary team, we were able to establish the correct diagnosis and successfully prevent recurrence.