Primary meningeal pleomorphic xanthoastrocytoma: Case report and review of literature

Abstract

Pleomorphic xanthoastrocytoma (PXA is a rare low-grade glial neoplasm of the central nervous system accounting for less than 1% of all astrocytomas. Similar to other gliomas, it can rarely arise from glial nests in the meninges, manifesting as an extra-axial mass mimicking a meningioma.

In this article, we report the fourth case, so far, of a solitary primary meningeal PXA in a 23-year-old woman who presented with temporal seizures and features of raised intracranial pressure.

Introduction

Pleomorphic xanthoastrocytoma (PXA) is an uncommon astrocytic tumor accounting for less than 1% of all astrocytomas (1). Kepes was the first to describe it as a pathologically distinct entity in 1979 (2). In 1993, it was formally incorporated in the WHO classification system of central nervous system tumors as a WHO grade II tumor. In 2007, it was regarded as a Grade II benign glioma, with the possibility of signs of anaplasia. Therefore, in the 2016 edition, PXAs with anaplastic features were upgraded to Grade III named “anaplastic PXA”.

Histologically, PXA is characterized by pleomorphic and lipidized cells, multinucleated giant cells, and eosinophilic granular bodies in an inflammatory background.

Similar to other gliomas, it rarely occurs in the extra-axial component. This report describes the fourth case of a solitary extra-axial PXA in a 23-year-old woman.

Case Description

A 23-year-old woman with no medical history presented to our emergency with repeated episodes of a rising sick feeling in her stomach, similar to being on a roller coaster followed by a short period of confusion and difficulty speaking. On admission, physical examination showed no abnormalities.

We suspected the diagnosis of temporal seizures. Therefore, a brain MRI was performed revealing an extra-axial dura-based lesion in the right temporal fossa. The tumor had two components solid and cystic. The sold mass measuring 22*28*20 was isointense on T1-weighted images, isointense on T2-weighted images, and heterogeneously enhanced (Figure 1).

After preoperative evaluation, the patient underwent surgery. A right temporal craniotomy was performed. Intraoperatively, the tumor was extra-axial, grayish-white, and highly vascular. We were able to achieve a gross total resection since the tumor was well demarcated from the surrounding brain.

On histopathological examination (Figure 2), hematoxylin and eosin-stained sections showed a tumor composed of spindle and epithelioid cells arranged in sheets and fascicles admixed multinucleated giant cells. The neoplastic cells had multivacuolated foamy cytoplasm and hyperchromatic nuclei with anisonucleosis. There were no mitoses or necrosis.

On the immunohistochemical examination (Figure 3), the neoplastic cells were positive to glial fibrillary acidic protein (GFAP), PS100, Vimentin, and Reticulin. In conclusion, the final diagnosis was a temporal extra-axial PXA.

The postoperative course was uneventful and the patient was seizure-free. She was discharged from the hospital three days later with no adjuvant therapy.

During a follow-up period of 2 years, the patient remained seizure-free. MRI of the brain was performed 18 months after surgery confirmed the absence of tumor recurrence (Figure 4).

Discussion

Similar to other gliomas, PXA rarely occurs in the extra-axial compartment causing primary meningeal gliomas (PMG). PMG may occur as a solitary mass or as diffuse meningeal involvement. We reviewed the relevant literature and identified only 31 cases of a solitary meningeal glial mass reported in English literature (3). Most PMG were astrocytomas (53.3%) followed by glioblastomas (30%) (3,4). To our knowledge, we are presenting the fourth case of an extra-axial PXA (Table).

Kepes originally suggested that PXAs may be derived from subpial astrocytes (2). Lehman and Giannini extrapolated to contemporary tumor stem cell theory would implicate cortical radial glial or cortical or leptomeningeal pluripotent neural progenitor cells derived from radial glia or neural crest cells in the development of PXAs

In our case, the intraoperative findings suggested an extra-axial mass arising from dura matter and lacking connection with brain parenchyma. However, the histopathological examination confirmed the diagnosis of PXA.

Typically, PXA consists of solid and cystic components on imaging. In contrast-enhanced computed tomography imaging, the cystic component is hypodense. The solid component typically appears hypo to isodense, but can occasionally be hyperdense, with areas of calcification seen in the solid component (1). However, it can be presented as a superficial mass with leptomeningeal contact (3,5). Therefore, these tumors should be considered as a differential diagnosis of intracranial meningiomas.

Due to the lack of reported data, there are no formal guidelines published on the management of PMGs. Treatment options include surgical resection followed by adjuvant therapy including radiotherapy with or without systemic therapy. In the management of parenchymal PXAs, multiple studies concluded that the importance of the extent of resection is a reliable prognostic factor for overall survivals (OS) and progression-free survival (PFS). Therefore, gross total resection (GTR) should be the goal of the surgeon (1,6). Adjuvant therapy has been generally considered minimally effective or ineffective for the treatment of PXAs. A meta-analysis of 167 patients with grade II PXA did not demonstrate an association between adjuvant therapy with improved oncologic outcomes (6). For primary meningeal PXAs, all reported cases were treated with surgery, 2 cases with subtotal resection, and 1 case with gross total resection.

The overall prognosis of PXA is relatively favorable. The OS of PXA is favorable with 5-year survival rates of >75%. However, monitoring for recurrence and malignant transformation is warranted since the recurrence rate of PXA following surgical resection is about 30% within 5 years and 40% within 10 years (7), and 10-20% undergo an anaplastic transformation (3). In his meta-analysis of 167 patients, Mallick found out that the estimated median OS was 209 months, and the estimated median PFS was 48 months (6).

Conclusion

PXA is a rare tumor ranging from WHO grade II to III. Solitary extra-axial dura-based PXA is an extremely rare entity with only 3 reported cases in the English literature excluding the present case.

Because of the rarity of the disease, there are no standardized guidelines for the management of solitary extra-axial primary meningeal PXA. However, as it is for parenchymal PXA, it is plausible that the extent of surgical resection is strongly predictive of recurrence-free survival.

Declarations

Funding

None.

Acknowledgment

None.

Conflicts of interest

The authors declare that they have no conflicts of interest concerning this article.

Statement of Ethics

Ethics approval was not required for this study.

Consent to Participate/for Publication

Consent to participate and consent for publication were obtained from our patient.

Code Availability

Not applicable.

Data availability Statement

All data are available as part of the article and no additional source data are required.

Authors’ Contribution

Patient management: Mohamed Amine Hadj Taieb, Kais Maamri and Emna Mili

Data acquisition: Mohamed Amine Hadj Taieb, Mohamed Boukhit

Manuscript preparation: Mohamed Amine Hadj Taieb, Kais Maamri and Mohamed Boukhit

Image Selection: Mohamed Amine Hadj Taieb, Ghassen Elkahla and Amine Trifa

Manuscript review: Mehdi Darmoul

References

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2. Kepes JJ, Rubinstein LJ, Eng LF. Pleomorphic xanthoastrocytoma: a distinctive meningocerebral glioma of young subjects with relatively favorable prognosis. A study of 12 cases. Cancer. nov 1979;44(5):1839‑52.
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6. Mallick S, Benson R, Melgandi W, Giridhar P, Rath GK. Grade II Pleomorphic Xanthoastrocytoma; a meta-analysis of data from previously reported 167 cases. J Clin Neurosci Off J Neurosurg Soc Australas. août 2018;54:57‑62.
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Table

Table: Information summary of the reported cases of primary meningeal PXA in English literature.