Three-dimensional analysis of pathological characteristics of a microaneurysm.
The etiology of Charcot-Bouchard microaneurysms (MAs), especially before rupture, has been unclear.


METHODS
A surgical specimen of an MA was removed from an acute intracerebral hemorrhage in a 69-year-old man. The MA was fixed with formalin and embedded in paraffin, and serial sections were cut and stained by the Azan and Elastica van Gieson methods and immunohistochemically. Three-dimensional reconstructive analysis was performed.


CONCLUSIONS
The MA presented as local enlargement of an artery with a maximal diameter of 840 microm, but was not ruptured. The wall of the MA consisted of thickened, fine collagen fibrils, which were found to be similar to adventitia immunohistochemically, but with no internal elastic lamina or medial smooth muscle layer. The lumen was empty, with no mural thrombi, but the inner wall endothelial cells had expanded from the normal and/or residual arterial wall, which suggested that the MA had been present for a long period of time. Because the bare wall of the MA consisted of thickened collagen fibrils, the MA was not ruptured, but the possibility of rupture in the future was deemed high, with the risk of intracerebral hemorrhage.
Kojima
H
H
Department of Clinical Neuropathology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan. hkojima-path@umin.net
Eguchi
H
H
Mizutani
T
T
Tanaka
K
K
Kikuchi
Y
Y
Fukudome
N
N
D000368:Aged; D018952:Antigens, CD34 / Q000378:metabolism; D002536:Cerebral Arteries / Q000378:metabolism / Q000473:pathology; D003094:Collagen / Q000378:metabolism; D006801:Humans; D021621:Imaging, Three-Dimensional; D002532:Intracranial Aneurysm / Q000378:metabolism / Q000473:pathology*; D008297:Male; D014057:Tomography, X-Ray Computed
D018952:Antigens, CD34; D003094:Collagen