Myocardial accumulation of labeled phosphate in malignant pericardial effusion.

Recognition of the presence of a malignant pericardial effusion is important because of the insidious onset and life-threatening potential. This report presents data on three patients with metastasizing carcinoma of the breast, all admitted with a presumptive clinical diagnosis of malignant pericardial effusion. Two of the three revealed a diffuse concentration of Tc-99m PPi within the myocardium. In these cases the diagnosis was confirmed by identification of malignant cells in the pericardial fluid. We suggest that the use of labeled phosphate agents may allow early recognition of myocardial involvement in patients with disseminated neoplasm that results in malignant pericardial effusion.