Malignant Astrocytoma Six Years after the Resection of a Cerebral Metastatic Cardiac Myxoma

We describe a woman who had a total resection of a cardiac myxoma followed 8 months later by a hemorrhage in the right frontal lobe secondary to extravascular metastasis of the myxoma. Six years later, after an asymptomatic follow-up, she developed a recurrence of left-sided seizures and an enhancing mass in the same location as the previous tumor. At operation, a malignant astrocytoma was demonstrated. Cardiac myxoma is a true neoplasm with benign histology, which may be associated with heart failure, systemic illness, or peripheral embolization. The neurological manifestations of embolization may include no symptoms, acute or delayed infarction, and intravascular proliferation with aneurysmal dilatation and potential for hemorrhage. The development of extravascular metastatic tumor deposits has been reported previously in only three histologically verified cases. Once the integrity of the blood vessel wall is destroyed by the tumor, a portal of entry is established for tumor cell proliferation in the brain parenchyma. There is no known association between a metastatic cardiac myxoma and a malignant glioma in the literature. Several possibilities for the occurrence of these two neoplasms are discussed.