The primary carcinoma of the fallopian tube is a rare disease with a bad prognosis. In a patient suffering from this disease a floating, intracardial structure occurred during systemic chemotherapy. An MRI was used to distinguish between metastasis and thrombus. The size of the thrombus decreased under anticoagulation und chemotherapy. The case showed that imaging methods like CT and MRI are useful in differential diagnosis between thrombus and metastasis. The primary carcinoma of the fallopian tube is a rare disease with a bad prognosis. In a patient suffering from this disease a floating, intracardial structure occurred during systemic chemotherapy. under anticoagulation und chemotherapy. The case showed that imaging methods like CT and MRI are useful in differential diagnosis between thrombus and metastasis.