[Monostotic fibrous dysplasia of the cranial vault: a case report].

Fibrous dysplasia, when it occurs in the craniofacial region, mostly involves the skull base and is rarely localized in the cranial vault. Although there have been several reports on magnetic resonance imaging (MRI) findings of fibrous dysplasia involving the skull base, cases occurring in the cranial vault have seldom been reported. We describe here a rare case of monostotic fibrous dysplasia that occurred in the parietal bone and discuss the characteristics of the MRI findings. A 47-year-old female was admitted to our hospital with a complaint of vertigo. A computed tomography (CT) scan did not reveal any intraparenchymal lesions in either the infra- or supratentorium, and her vertigo improved immediately without any treatments. However, a solitary osteolytic lesion was found incidentally in the left parietal bone. MRI showed that the lesion demonstrated hypointensity on T1-weighted images and hyperintensity on T2-weighted images, and was enhanced heterogeneously following injection of Gadolinium-DTPA. Removal of the parietal bone containing the lesion was performed according to the patient's wishes. The histopathological findings of the removed tissues corresponded to fibrous dysplasia. Although it is well known that craniofacial fibrous dysplasia demonstrates iso- or hypointensity on T1- as well as T2-weighted images, in the present case, the lesion showed apparent hyperintensity on T2-weighted images. These findings suggest that fibrous dysplasia can display various MR intensities depending on its origin.

Pathological and immunohistochemical findings of an autopsy case of adult moyamoya disease.

Moyamoya disease is vaso-occlusive disease involving the arteries of the circle of Willis that is accompanied by a compensatory recruitment of a vascular network. The pathological and immunohistochemical findings of an autopsy case of hemorrhagic moyamoya disease in a 69-year-old woman are described in the present report. The autopsy findings of the brain revealed cerebral and intraventricular hemorrhage with edema. The left anterior cerebral artery, bilateral middle cerebral arteries and left posterior cerebral artery were marked narrowing, and the other arteries revealed mild narrowing. Microscopically, the arteries of the circle of Willis showed narrowed lumen, fibrocellular intimal thickening, marked tortuousness of internal elastic lamina and attenuation of media. The thickened intima was composed of smooth muscle cells. The vessels with dilated or irregular-shaped lumen suggested abnormal vascular networks demonstrated by angiography. In this case, no correlation between the abnormal vascular network and expression of VEGF or VEGF receptor was disclosed. It was hypothesized that abnormal vascular networks might be composed of collateral vessels in relation to various pathological changes of the arteries, such as occlusion and stenosis, and intracranial hemorrhage in patients with moyamoya disease might occur as a result of rupture of arteries including abnormal vascular networks.