Ectopic meningioma in a patient with neurofibromatosis Type 2: a case report and review of the literature

Abstract

Ectopic meningioma occurring in the region of parapharyngeal space is rare in clinical practice and brings great challenge in its diagnosis. This report details such a case in a 14-year-old girl with neurofibromatosis Type 2, which is a highly infrequent association. The clinical manifestations, imaging findings, and pathological manifestations are described, and the relevant literature is reviewed to highlight characteristic imaging findings of ectopic meningiomas.

Figure 1.

The patient, a 14-year-old girl, presented with a painless mass in the right retroauricular area.

Figure 2.

Nasopharyngeal MRI examination reveals a large, well-circumscribed mass in the right parapharyngeal space. The mass is isohypointense on T ₁WI (a) and slightly hyperintense on T ₂WI (b); it is accompanied by multiple focal hypointensities that may represent calcification. Marked but heterogeneous enhancement was observed on axial post-contrast T ₁WI after the administration of gadolinium (c). The sagittal post-contrast T ₁WI (f) shows that the mass had invaded the carotid space—as well as the parotid and perivertebral space—and encased major carotid vessels. DWI (d) revealed a restriction of diffusion, with an average ADC value of 699.7 × 10⁻⁶ mm² s^{– 1} (e). ADC, apparent diffusion coefficient; DWI, diffusion-weighted imaging; T ₁WI,T ₁ weighted imaging; T ₂WI,T ₂ weighted imaging.

Figure 3.

An axial post-contrast T ₁WI (a–c), reveals multiple nodular masses in the frontal region and the midline (black arrows). There were bilateral masses in the bilateral cerebellopontine angle, which broadened bilateral internal auditory canal. They showed significant contrast enhancement after gadolinium administration (white arrow). There were bilateral thickening C6-C7 spinal nerve root. These roots were isointense on both coronal T ₁WI (f) and T ₂WI (g). In addition, obvious nodular enhancement is seen on the coronal post-contrast T ₁WI (h) (red arrows). The coronal post-contrast T ₁WI shows involvement of the right hypoglossal canal (yellow arrows). T ₁WI,T ₁ weighted imaging; T ₂WI,T ₂ weighted imaging.

Figure 4.

(a) H-E staining shows psamomma bodies in sheets of cells with a meningothelial pattern (H-E;×200). (b) Immunohistochemistry shows positive staining for EMA. (Magnification × 100). EMA, epithelial membrane antigen; H-E, haematoxylin and eosin.