Primary Epithelioid Angiosarcoma of the Right Atrium Presenting With Symptomatic Bradycardia: A Case Report.

Primary cardiac angiosarcoma is a rare and aggressive malignancy that mainly affects the right atrium of the heart. In this report, we present a rare variant known as cardiac epithelioid angiosarcoma. Due to its rarity, the epidemiology and pathogenesis of this disease are not well understood. We present the case of a 44-year-old woman who presented with palpitations, chest pain, and symptomatic bradycardia. Multimodal imaging identified a large, sessile right atrial mass. The location of the mass near the sinoatrial node region likely contributed to the patient's bradycardia. The patient underwent surgical resection with bovine pericardial patch reconstruction. Histopathology favored epithelioid angiosarcoma, and the margins were unclear due to specimen fragmentation. The postoperative course was complicated by junctional rhythm bradyarrhythmia requiring pacing. Comprehensive staging, including brain MRI and CT of the chest, abdomen, and pelvis, ruled out distant metastasis. The patient was deemed not to be a candidate for radiation therapy due to the tumor's location in the heart. Although adjuvant AIM chemotherapy (doxorubicin, ifosfamide, mesna) was recommended by oncology, the patient opted for observation, given the limited expected benefit of chemotherapy. This case highlights the complexity of managing primary cardiac angiosarcoma, particularly when standard therapeutic options are limited, and underscores the need for individualized, multidisciplinary care.