Fatal cardiac tamponade following cytoreductive surgery for serous carcinoma of the ovary

•Pericardial effusion may be present early in the disease process in patients with ovarian cancer.•Even a small pericardial effusion may become clinically apparent in the setting of concomitant pleural effusion(s).•Cardiac tamponade should be considered in the differential diagnosis of postoperative hemodynamic instability to facilitate timely intervention.