PMC8769410_01
Axial preoperative MRI reveals an extra-axial mass lesion in the left
parieto-occipital region, including two well-demarcated round mass
components. (A) Diffusion-weighted imaging shows low-intensity,
round masses and a high-intensity main tumor. (B) T1-weighted
imaging shows isointense findings for both round masses and the main tumor.
(C) T2-weighted imaging shows hypointense round masses and
a hyperintense main tumor. (D) Contrast-enhanced MRI shows
enhancing effects on both components, with higher enhancement of the main
tumor compared to the round masses. MRI: magnetic resonance imaging.
nmccrj-8-215-g001.jpg
PMC8769410_01_nmccrj-8-215-g001.jpg
F1
Preoperative MRI revealed an extra-axial mass lesion in the left parieto-occipital region, appearing to contain two well-demarcated round mass components (Fig. 1). Diffusion-weighted MRI showed hypointense round masses within a hyperintense main tumor (Fig. 1A). T1-weighted imaging revealed isointense round masses within the main tumor (Fig. 1B). T2-weighted imaging demonstrated two low-intensity, round masses and a high-intensity main tumor (Fig. 1C). Contrast-enhanced MRI showed enhancement of both components, with higher enhancement of the main tumor compared to the round masses (Fig. 1D).
Intraoperative photo shows a white, isolated round mass (short arrows)
buried in the reddish main tumor (*), which has no dural attachment.
nmccrj-8-215-g002.jpg
PMC8769410_01_nmccrj-8-215-g002.jpg
F2
Two white masses were identified within the main tumor, with neither showing dural attachment (Fig. 2).
Postoperative MRI at 1 year after surgery demonstrates total removal of
the tumor. MRI: magnetic resonance imaging.
nmccrj-8-215-g003.jpg
PMC8769410_01_nmccrj-8-215-g003.jpg
F3
MRI one year after surgery showed no recurrence (Fig. 3).
Photomicrographs of pathological specimens. green bar, 100 mum; red
bar, 1000 mum. (A) Specimen of the main tumor shows
typical meningothelial meningioma. HE: original magnification x20.
(B) A specimen of a white, round mass buried in the main
tumor shows typical fibrous meningioma. HE, original magnification
x20. (C, D) Specimen from the border of these
components. The arrowheads (C) and the short arrows
(D) indicate the border between meningothelial and fibrous
subtypes. These two different subtypes of meningioma separately exist with
clear margins. HE, original magnification x4 (C),
x20 (D). HE: hematoxylin and eosin.
nmccrj-8-215-g004.jpg
PMC8769410_01_nmccrj-8-215-g004.jpg
F4
Microscopic examination of a specimen from the main tumor showed typical meningothelial meningioma (Fig. 4A) while a specimen from one of the buried mass lesion revealed typical fibrous meningioma (Fig. 4B). The margins of both meningioma subtypes were clear, with no evidence of transitional mixtures of either subtype of meningioma (Fig. 4C and 4D).