Ruptured Middle Cerebral Artery Aneurysm with Intramural Myxoid Degeneration in a Child

Abstract

A 9-year-old girl presented with a subarachnoid hemorrhage. Cerebral angiography showed a saccular aneurysm arising from the horizontal portion of the right middle cerebral artery. The aneurysm was successfully clipped, and the dome of the aneurysm was excised for pathological study. Histological examination of the aneurysm wall showed that the entire thickness of the wall showed an increased myxoid degeneration. No dissection was present. Most intracranial aneurysms in childhood are believed to be of the saccular type similar to that in adults, but the pathogenesis of the aneurysm formation remains controversial. Myxoid degeneration may cause intracranial saccular aneurysm with eventual rupture, even in the absence of dissection. This is the first case reported of a ruptured saccular aneurysm caused by myxoid degeneration in a child. The possible pathophysiology is discussed.

Evolution of Management of Intracranial Aneurysms in Children

“…A histopathological analysis of tissue obtained from aneurysms (n = 10) was found in 9 studies. 41 –49 Absence or irregular disruption of the internal elastic membrane was observed in all cases. An inflammatory cell infiltration with fragments of the internal elastic membrane detected within macrophages and multinucleated giant cells was reported in a boy who succumbed to subarachnoid hemorrhage.…”

Multiple Cerebral Aneurysms Caused by Cardiac Myxoma

“…Intracranial myxomatous aneurysms occur with the highest frequency in the peripheral arterial branches of the anterior and middle cerebral arteries, although central fusiform aneurysms have been reported. Saccular aneurysms are a less common feature of myxomatous emboli 26 . Myxomatous aneurysms located on extracerebral arteries are very rare in comparison with cerebral ones.…”

Embolic atrial myxoma with neoplastic aneurysm formation and haemorrhage: a diagnostic challenge

“…In the differential diagnosis of embolic cardiac myxoma, the possibility of metastatic myxoid sarcomas and/or of a tumour of endothelial origin [14] should be entertained, while the rare presence of ‘glandular’ elements may raise the question of metastatic adenocarcinoma [15]. The possibility of a non‐neoplastic process, such as organizing clot [16] or myxoid degeneration of an aneurysmal wall [17] should also be considered. Primary intracranial myxomas are extremely rare and generally present as extraaxial dura based masses mimicking meningiomas [18,19; personal observation].…”