RESUMO
INTRODUCTION: Primary cardiac tumors are rarely seen in the general population and only a subset are classified as cardiac papillary fibroelastoma. CASE PRESENTATION: A 59-year-old female that presented for unresponsiveness and cardiac arrest required 4 rounds of cardiopulmonary resuscitation and intubation. Laboratory investigations showed uncompensated respiratory acidosis, hyperkalemia, and elevated troponins. A chest computed tomography angiogram illustrated an acute right pulmonary embolism and a right atrial filling defect. Furthermore, an echocardiogram demonstrated a normal ejection fraction and a large, pedunculated, mobile, and non-valvular echodensity that was attached to the right atrium endocardium. Therefore, the patient was started on a heparin infusion and catheter-directed thrombolysis; however, the mass persisted. A surgical excision was performed, and a 40 mm was removed. The patient was diagnosed with a papillary fibroelastoma based on the clinical symptoms, imaging, and histological findings. CONCLUSION: This patient's papillary fibroelastoma had multiple rare features including right atrial origin, large size, non-valvular location, and developed symptoms. Although this disease can be initially fatal, the patients typically have a favorable prognosis after a successful excision.