B2 Thymoma with Intracardiac Extension Presenting as Superior Vena Cava Syndrome: Case Report and Literature Review

This article aims to emphasize the importance of considering invasive thymoma in the differential diagnosis of mediastinal masses and highlights the critical role of timely surgical and oncological management in improving patient outcomes.

We present the case of a 70-year-old woman who presented with signs of superior vena cava syndrome, including dyspnea, facial swelling, and fatigue. Advanced imaging and intraoperative findings revealed a large anterior mediastinal mass infiltrating the left brachiocephalic vein and superior vena cava, extending into both the right atrium and right ventricle. Surgical intervention was performed, and histopathological analysis confirmed B2 thymoma with a high Ki-67 proliferation index. Despite surgical intervention, the patient's condition deteriorated, and she ultimately succumbed to the disease.

To the best of our knowledge, this is the first reported Bosnian case of B2 thymoma invading the brachiocephalic vein and superior vena cava and infiltrating both the right atrium and ventricle, causing superior vena cava syndrome. Despite their rarity, thymomas should always be considered in patients presenting with an enlarged mediastinum.