Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 57 1 2019 02 13 68 71 EN Aghigh Heidari Department of Anesthesiology, Imam Ali Hospital, Kermanshah University of Medical Sciences, Kermanshah, Iran. Fereidoun Sabzi Department of Cardiac Surgery, Imam Ali Hospital, Kermanshah University of Medical Sciences, Kermanshah, Iran. 2017 09 09 2017 12 19 Metastatic involvement of cardiac valve and pericardium mimicking a cardiac valve pathology accompanied with cardiac tamponade is a rare phenomenon. These metastases commonly arise from the lymphoreticular system, the pulmonary system, and breast. Metastatic spread of breast carcinoma to the cardiac valve is exceedingly rare, and only two case reports have been detected in English literature so far. We report a rare case of a patient with adenocarcinoma of the breast, which presented with severe mitral valve regurgitation and pericardial effusion which was managed urgently with mitral valve replacement. Our case shows the probability of combined metastatic pericardial and valve involvement in patients with breast adenocarcinoma. The patient was treated with mitral valve replacement and intrapericardial infusion of cisplatinum drug to control possible recurrent effusion. https://acta.tums.ac.ir/index.php/acta/article/view/6699 https://acta.tums.ac.ir/index.php/acta/article/download/6699/5212