case_images: PMC5672993_01
case_images: (A) Plain skull x-ray shows an osteolytic lesion in the left frontal bone (arrow). (B) Bone window computed tomography shows a solitary osteolytic lesion.
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case_images: PMC5672993_01_10.1177_1179547617738231-fig1.jpg
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case_images: Skull x-rays and computed tomography (CT) showed an osteolytic lesion measuring approximately 3 cm x 4 cm in the left frontal bone (Figure 1).
case_images: (A) T1-weighted and (B) T2-weighted axial MR images show an isointense intraosseous mass that is hyperintense on (C) FLAIR image. The mass is associated with an intradural cyst showing similar intensity to CSF on T1-weighted and T2-weighted images and slightly hyperintense compared with CSF on FLAIR image. Gadolinium-enhanced (D) axial, (E) coronal, (F) and sagittal MR images demonstrate homogeneous enhancement of the mass and dura mater but no enhancement of the cyst wall. Note that the dura mater is seen along the inner margin of the mass, bulges inward as a hypointense band on the (B) T2-weighted image, and appears as a more enhanced band on gadolinium-enhanced (D, E) T1-weighted images. Arrows indicate tumor with cyst, and arrowheads indicate dura mater between the mass and cyst. CSF indicates cerebrospinal fluid; FLAIR, fluid attenuated inversion recovery; MR, magnetic resonance.
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case_images: PMC5672993_01_10.1177_1179547617738231-fig2.jpg
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case_images: Magnetic resonance images demonstrated a mass lesion within the diploe that was isointense on T1-weighted and T2-weighted images and hyperintense on diffusion-weighted and fluid attenuated inversion recovery images (Figure 2).
case_images: Hematoxylin-eosin-stained sections of intraosseous tumor:(A) x10 and (B) x40; dura mater:(C) x10 and cyst wall:(D) x40. (A, B) Transitional meningioma is shown with whorl formation and an increased proportion of collagenous fibers in the skull. Tumor cells have infiltrated through (C) the dura mater and are present in (D) the cyst wall.
case_images: 10.1177_1179547617738231-fig3.jpg
case_images: PMC5672993_01_10.1177_1179547617738231-fig3.jpg
case_images: fig3-1179547617738231
case_images: Histologic evaluation revealed benign transitional meningioma with whorl formation in all excised specimens including the skull, dura mater, and cyst wall (Figure 3).