Cardiac myxoma represents mostly benign, slowly proliferating tumor which are believed to derive from multipotent mesenchymal cells of the endocardium [5]. It may present with many clinical syndromes outside the cardiac events. It was reported that about 20–30% of patients with atrial myxoma had neurological complications [3, 6, 7]. The CNS manifestations include progressive headache, nausea or vomiting due to the increase of intracranial pressure, limbs or body weakness or numbness and new onset of seizure [6]. In the majority of cases such complications appear in rather young patients and are usually caused by cerebral embolism and subsequent cerebral infarcts [7, 8]. Cerebral metastatic, aneurysm formation and subsequent subarachnoid or intracerebral hemorrhage are rare but well-known complications of atrial myxoma in adults [9]. Furthermore, aneurysms secondary to myxoma can be a delayed presentation and can be found before resection of myxoma or even after resection of myxoma [10, 11], as in this case. So it is necessary to have a screening with regard to cerebral complications in patients with atrial myxoma. Imaging studies as CT, MRI and cerebral angiography should be performed in every patient with atrial myxoma to detect aneurysms and cerebral lesion. The echocardiography is also suggested for every patient presenting a cerebral infarction with aneurysm [12].
Brain metastases are usually found at the same time or few months after the diagnosis of cardiac myxoma. Other systemic metastases of cardiac myxoma concomitant with the brain have been reported in kidney, pancreas, bone, muscles, skin and stomach [4, 13]. All of these metastases can be explained by the dislodgement of the friable and spongy component of the atrial myxoma into the systemic circulation [14]. The myxomatous aneurysm formation process remains unclear. Three causes of cerebral aneurysm formation have been proposed [14, 15]. One is the vascular damage hypothesis. They postulated that large myxomatous emboli cause vascular occlusion and perivascular damage with subsequent scarring and pseudoaneurysm formation. The other cause is the cerebral vessels are infiltrated by myxoma cells via vasa vasorum causing the destruction of arterial wall architecture, which is similar to the mechanism of mycotic aneurysms. The last cause that has been suggested is the neoplastic process. Several authors have observed myxomatous cells in the aneurysmal vessel. They hypothesized the myxomatous cells could remain viable and penetrate intact or damaged endothelium at the site of final lodgement, with subintimal growth, destruction of the wall, and fibroblastic proliferation. This neoplastic process was accompanied by connective tissue proliferation and a mild inflammatory reaction, and neovascularization in the affected arterial wall may lead to minor bleeding.
Cardiac surgery is the method of choice in treating myxoma [16]. And once the diagnosis is established, surgery should be performed promptly to reduce the possibility of embolic complications or sudden death. For the surgery, three important points should be noted to prevent recurrence: 1) multifocal tumors in heart chambers should not be omitted during operation [17]; 2) cardiac appendages should be removed, sutured and repaired if necessary [18,19,20,21]; 3) tumors must be avoided from fragmentation and embolization [19].
Nevertheless, there are no precise guidelines for possible treatment procedures of neurological complications [5, 14]. The use of anticoagulants or antiplatelet agents should be considered in order to prevent further emboli. Surgery is appropriated in cases with few isolated aneurysm or brain metastases or when one of the lesions is life threatening. Moreover, chemotherapy with doxorubicin or ifosfamide with or without radiotherapy of the whole brain could be administrated to patients with multiple brain metastases in order to obtain a longer period of time without recurrence [22]. Furthermore, it is noted that most of the aneurysms are fusiform in shape, and clipping or coiling treatment can be limited. Though there are successful cases of endovascular coiling for enlarging aneurysms, overall evidence documenting stability of cerebral aneurysms over several years gives support to conservative treatment management options [12, 23,24,25].
Thus, long term follow-up of the patients with atrial myxoma even after complete surgical excision is recommended [16]. Thorough explanation of the potential risks of recurrence of the cardiac tumor, the late development and enlargement of cerebral lesions are necessary. Vigorous work-up must be pursued if the patient again becomes symptomatic or develops new central nervous system manifestations.
