PMC5099298_01
Skull radiographic images in antero-posterior view (a) and lateral view (b). A club-shaped lucent bone defect (arrowheads) was visible in the lateral view
40064_2016_3607_Fig1_HTML.jpg
PMC5099298_01_40064_2016_3607_Fig1_HTML.jpg
Fig1
Radiography showed the presence of a linear bone deficit in the left parietal diploe (Fig. 1).
CT images 5-years prior to the operation (a) and immediately prior to the operation (b). A lesion with a bone defect in the left parietal bone expanded over 5 years (arrowheads)
40064_2016_3607_Fig2_HTML.jpg
PMC5099298_01_40064_2016_3607_Fig2_HTML.jpg
Fig2
Computed tomography (CT) imaging identified hyperosteosis in the skull around the bone deficit, but the lesion did not yet eroded the outer layer of the skull (Fig. 2b). After comparing this CT image with a previous one that had been obtained 5 years before at another hospital (Fig. 2a), we determined that the lesion had expanded.
MRI scans prior to the operation (a-d) and after the operation (e). Each image showed a lesion (arrowheads) in the left parietal bone. A magnified clipping of the lesion is accompanied in the rectangle with each axial image (d, e). The inside of the lesion appeared with mixed intensity on T1- (b) and T2-weighted (d) images, and a part of the lumen was clearly enhanced with gadolinium contrast media (a, c). The intensity of the inside showed as high intensity on T2-weighted images after the operation (e)
40064_2016_3607_Fig3_HTML.jpg
PMC5099298_01_40064_2016_3607_Fig3_HTML.jpg
Fig3
T1- (Fig. 3b) and T2-weighted (Fig. 3d) images and was slightly enhanced with gadolinium contrast media (Fig. 3c). The main part of the inside appeared at iso- and low intensities on T1- (Fig. 3b) and T2-weighted (Fig. 3d) images, respectively, and it was clearly enhanced with gadolinium contrast media to the same extent as vessel lumens (Fig. 3a, c). T2-weighted images. The main part of the inside of the sac showed low intensity prior to surgery (Fig. 3d) but changed to high intensity after surgery (Fig. 3e), suggesting that it had been filled with thrombi.
Reconstructed three-dimensional images of pre-operative CT angiography (a, b) and post-operative magnetic resonance venography (c, d). A club-shaped lumen filled with blood (arrowheads) disappeared after ligation of feeding diploic veins
40064_2016_3607_Fig4_HTML.jpg
PMC5099298_01_40064_2016_3607_Fig4_HTML.jpg
Fig4
In the 3D reconstructed images, a club-shaped lesion was visible in the venous phase (Fig. 4a, b). In addition, magnetic resonance venography showed that there was no longer any blood inflow into the sac (Fig. 4c, d).
Histological images of a membranous wall of varix-like venous sac. The upper image was in a low power field (a Hematoxylin and eosin staining, x150), and the lower images were in high power fields (b Hematoxylin and eosin staining; c CD31 staining; d silver staining, x400). The membrane mainly consisted of a thick layer of fibrous tissues. Osseous tissues (asterisk) were attached to the upper side of the membrane (a). The other side was lined by a single layer of endothelial cells (b), which showed positive CD31 staining (c). Silver staining of the membrane was negative, indicating the absence of elastic laminae (d)
40064_2016_3607_Fig5_HTML.jpg
PMC5099298_01_40064_2016_3607_Fig5_HTML.jpg
Fig5
Histopathological study of the lesion showed a membranous wall that consisted mainly of fibrous tissues with scattered spindle cells (Fig. 5a). The membranous wall was considered to be a dilated venous wall as it contained a single layer of luminal endothelial cells (Fig. 5b) that was positive for CD31 staining (Fig. 5c), but lacked elastic laminae after silver staining (Fig. 5d). 