Angiomatous, Predominantly Cystic Meningiomas: A Case Report and Literature Review of a Unique Group of Meningiomas

Abstract

Meningiomas are the most common intracranial benign tumors. Among them, cystic angiomatous meningiomas are very rare entities, making preoperative differentiation with other tumors challenging. We present a case of parasagittal angiomatous meningioma with a large associated cyst that mimicked a hemangioblastoma on preoperative imaging. It was treated surgically. We also performed a literature review and identified a total of 10 articles in the English language, describing a few similar cases of cystic angiomatous meningiomas. Conclusions: This report of a rare case of cystic angiomatous meningioma with a unique cystic presentation on preoperative imaging adds to the scarce body of literature on the topic. Surgery is ultimately the key method to make a diagnosis and to decompress the brain parenchyma in these patients.

Keywords: angiomatous meningioma; brain anatomy; brain tumors cns tumors; general neurosurgery; neurosurgical procedures.

Figure 1. Preoperative MRI findings

The images revealed a small contrast-enhancing lesion (white arrows) together with a large associated cyst in the paramedian left central region, suggestive of a hemangioblastoma (postcontrast T1 sequences in axial (A), coronal (B), and sagittal (C) views). T2 sequences did not show any signs of edema (D) MRI: magnetic resonance imaging

Figure 2. Intraoperative images after dural opening

The images show the complete nodule with broad dural attachment (see white arrow in B). The xanthochromatous fluid of the cystic portion of the lesion can be observed (A). The lesion was removed together with the adhering dura. A small area of adhesion to the cerebral cortex was evident but without clear parenchymal invasion (B, C, and D)

Figure 3. Histopathological examination

Immunohistochemical features of a typical angiomatous meningioma with large meningothelial cells (HE) within many small capillaries (PAS) and absence of reticulin within the tumor cells (Gomori) were observed. Low MIB-1 proliferative activity and positivity of epithelial membrane antigen (EMA), somatostatin receptor (SSTR2A), and progesterone receptor (PgR) support the diagnosis, and negative InhibinA stains rule out hemangioblastoma (A-H)