Malignant pericardial effusion and cardiac tamponade.

Cardiac tamponade due to malignant effusion, though rarely the initial manifestation of malignancy, is usually secondary to adenocarcinoma of the lung. Two cases are reported. One patient presented with cardiac tamponade; the other had diffuse cutaneous involvement of the left neck and shoulder two months before he presented with cardiac tamponade. Cytologic examination of both fluids revealed adenocarcinoma. Ultrastructural examination showed poorly differentiated adenocarcinoma in the first patient and bronchioloalveolar carcinoma in the second; carcinoembryonic antigen levels in the fluids were 9.4 ng/mL and over 60 ng/mL, respectively. The computed tomographic (CT) scans of both patients revealed mediastinal fullness with no lung involvement. Even in the absence of a pulmonary mass, lung carcinoma may be the likely primary in patients with malignant pericardial effusions.