Intraparenchymal meningioma in the parieto-occipital region: A case report of a diagnostically challenging tumor

Abstract

Background: Intraparenchymal meningioma is a rare entity of one of the most common brain tumors. It is challenging to diagnose preoperatively due to the vague clinical presentation and absence of stereotypical radiological features. These atypical features might mislead the differential to favor high-grade gliomas or brain metastasis.

Case description: We describe a case of a 46-year-old male who presented with vertigo, right-sided sensorineural hearing loss, and bilateral blurred vision. Contrast-enhanced magnetic resonance imaging of the brain revealed a large parieto-occipital contrast-enhanced mass with a multi-loculated cystic component and diffusion restriction but without dural attachment. A gross total reaction was achieved, and the histopathological results yielded a World Health Organization Grade I meningioma diagnosis. The patient exhibited no signs of recurrence after 2 years of follow-up.

Conclusion: Intraparenchymal meningiomas are difficult to identify without histopathological assessment. We emphasize the importance of considering this diagnosis when outlining an initial differential as it may direct management planning. Total surgical resection is the best treatment modality for such cases; however, radiotherapy is a valuable option. The prognosis of intraparenchymal meningiomas is generally favorable.

Keywords: Differential diagnosis; Intraparenchymal; Meningioma; Subcortical meningioma; Transitional meningioma.

Figure 1:

A contrast-enhanced axial brain computed tomography image (a and b) showing a right parieto-occipital lesion, well-demarcated, and enhanced capsule consisting of solid and cystic parts with perifocal edema and subtle midline shift to the left.

Figure 2:

(A-H) Brain magnetic resonance imaging was done preoperatively. (a) axial diffusion-weighted image showing diffusion restriction in the solid part of the lesion. Fluid attenuated inversion recovery sequence images in (b) axial and (c) coronal planes, in addition to (d) coronal and (e) axial T2-weighted images showing a large solid and cystic intra-axial mass in the right parieto-occipital region with surrounding vasogenic edema. (f) axial, (g) sagittal, and (h) coronal gadolinium-enhanced T1-weighted image demonstrating an enhanced lesion and multiple loculations in the cystic component with a thick irregular enhancement of the wall.

Figure 3:

Microscopic examination of hematoxylin and eosin (H and E) stained sections. (a and b) (H and E- �10) Proliferation of neoplastic meningothelial cells, infiltrating the dura. (c and d) (H and E- �20) Tumor cells are arranged in whorls, fascicles, and microcystic pattern. Psammoma bodies seen. (e) epithelial membrane antigen immunohistochemistry patchy positive staining and (f) Progesterone receptor immunohistochemistry positive nuclear staining.

Figure 4:

A brain magnetic resonance imaging was done 2-month postoperatively. Axial (a) Diffusion-weighted image, (b) FLAIR, and (c) contrast-enhanced T1-weighted images showing postoperative changes noted in the right parietal and occipital lobes with areas of gliosis and focal volume loss. Nodular areas of enhancement are seen at the surgical site, consistent with scarring-no evidence of residual disease or tumor recurrence.