A right atrial/auricular mass is most likely a hemangiosarcoma.
Other tumor types would include
The prognosis is typically poor; however, with chemotherapy and surgery (pericardectomy or pericardial window), these patients can typically have a high quality of life.
Their overall life expectancy is unfortunately short (typically 90-120 days). Consultation with an oncologist is highly recommended to discuss potential treatment strategies and the associated survival times and quality of life with each potential chemotherapeutic option