Classic presenting manifestations of cardiac myxoma include constitutional, obstructive, and embolic symptoms . Cerebral ischemia may be the most significant complaint despite cardiac dysfunction symptoms In patients with left atrial myxoma, 11%–45% of ischemic strokes could be induced by a small emboli which is detached from the myxoma [5, 6]. Cerebral infarction was the most common manifestation in up to 89% among myxoma patients with neurologic symptoms . Therefore, myxoma is less likely to be ignored in case of repeated ischemic stroke.
However, only a small fraction of patients with myxoma was found due to intracranial hemorrhages [6, 8]. Single hematoma or multiple scattered microbleeds, also subarachnoid hemorrhage might be present. These hemorrhages are usually related to previous cerebral infarction caused by myxoma [6, 8, 14, 16]. However, it is quite rare that repeated intracranial hemorrhages without definitive history of ischemic stroke or cardiac symptoms, could be the first and primary clinical presentation. The radiological finding in routine MR imaging, especially the hemosiderin signal around the lesions, strongly support the diagnosis of CA. Therefore, multiple CAs was misdiagnosed according to the clinical and MR features before admission.
Even SWI features of this patient imitate CAs. It is well known that SWI is crucial to diagnose multiple CAs, because it is very sensitive in detecting previous microbleeds according to the remaining hemosiderin with ferromagnetic composition [3, 10]. But in this case, SWI might be confusing. The presence of hemorrhagic lesions combined with numerous microbleeds in SWI indicated multiple CAs. However, considering embolic stroke afterwards, the visible microbleeds is also likely to be caused by unnoticed previous minor asymptomatic lacunar stroke, probably due to micro embolus detached from cardiac myxoma.
Embolic stroke after admission led us to diagnose cardiac myxoma eventually. But how did myxoma cause repeated hemorrhages without an obvious ischemic stroke before admission? It was reported that myxomatous aneurysms might be an alternative source of bleeding [7, 13, 16]. About 1/3 of patients treated for atrial myxoma may present with a cerebral aneurysm . In this case, the head MR angiography showed a suspicious aneurysm, but it is not responsible for all hemorrhages apparently. After reviewing previous literatures, it seems that intracranial hemorrhages of atrial myxoma are relatively rare, and may be repeated multiple hemorrhages, some bleeding co-exist with subarachnoid hemorrhage without angiographic evidence of aneurysms [2, 13]. Another explanation is that cardiac myxoma may break down and travel along the blood stream, and the metastasis can bleed inside . In this case, we believe that these intracranial hemorrhagic lesions may be mainly myxoma metastasis.
Although in this case, the patient did not have irreversible poor prognosis after repeated intracranial hemorrhages and ischemic event after admission, it should alert the clinicians to pay more attention to such various clinical features of myxoma. The repeated hemorrhagic signals in CT due to myxoma may hinder the clinicians to make a correct diagnosis of cerebral ischemia. However, if mxyoma cannot be detected in time, the hemostatic treatment according to the CT presentation may exacerbate cerebral ischemia and catastrophic results, such as acute cardiac dysfunction, ischemic stroke or sudden death, during anesthesia or around the perioperative period. Therefore, cardiac examination, such as echocardiography, should be performed as an alternative screening tool for cardiac myxoma, in case of unclear repeated multiple intracranial hemorrhages, markedly unmatched symptoms. Especially with unmatched symptoms.
There are no definite therapeutic guidelines about further intervention for this disease. Resection of the cardiac myxoma firstly is useful to eliminate the original sources of metastastic lesion, however which cannot completely abolish the risk of delayed cerebral aneurysm formation . However, because cerebral aneurysm from cardiac myxoma are probably multiple and rarely associated with intracranial hemorrhage, most of the patients can be managed conservatively . Antifibrinolytic drug such as aminomethylbenzoic acid can be used to prevent rebleeding . If severe intracranial hemorrhage due to myxoma do occur, excision of large intracranial hematoma and metastatic lesions remains supportive, and is useful in eliminating early neurologic symptoms . For this case, we believe that further intracranial lesions resection is more suitable than consevative therapy. Some authors also suggest that chemotherapy in combination with low-dose radiation for multiple lesions, but there are only four reported cases that received 25-60Gy brain radiation in previous studies,and one of these patients died of enlarging intracranial masses [1, 9, 13, 15].