Incidental pediatric intraparenchymal meningioma: illustrative case

Abstract

Background: Meningiomas are the most common benign tumors among CNS neoplasms. In the pediatric population, however, they account for only 0.4%-4.6% of all intracranial neoplasms; they are rare inside the brain parenchyma and are frequently confused with other entities, such as glioneuronal tumors and cavernomas, among others.

Observations: The authors describe the case of a 4-year-old male who presented to the emergency department for evaluation of periorbital cellulitis and was incidentally diagnosed with a brain tumor. MRI demonstrated an expansive heterogeneous lesion, 2.2 × 1.9 × 1.8 cm, in the left lingual gyrus. Spectroscopy and perfusion imaging suggested a low-grade glioneuronal tumor. After thorough discussion, the family and medical team elected to pursue surgical treatment. The patient had an uneventful postoperative recovery, and subsequent pathological and immunohistochemical analysis confirmed the diagnosis of a fibrous meningioma (WHO grade 1).

Lessons: Intraparenchymal meningiomas are a rare and misdiagnosed tumor, especially in the pediatric age group, and therefore are not usually considered in the differential diagnosis of intra-axial neoplasms in children. When suspected, surgery may be encouraged due to the tendency of these tumors to exhibit more aggressive behavior compared with adult meningiomas. https://thejns.org/doi/10.3171/CASE24611.

Keywords: case report; intra-axial meningioma; intraparenchymal meningioma; oncology; pediatric tumor.

FIG. 1.

Preoperative imaging. A: Axial CT scan without contrast demonstrating calcified left occipital and parasagittal lesion. B:Axial T1-weighted MR image with contrast demonstrating a tumor with heterogeneous enhancement by gadolinium. C:Sagittal T1-weighted MR image with contrast showing the lesion in the lingual gyrus without the dural tail sign. D: Axial T2-weighted MR image demonstrating the surrounding edema (arrows).

FIG. 2.

A and B: Histological sections reveal well-defined neoplasm, not encapsulated, characterized by the proliferation of spindle cells, with elongated nuclei, inconspicuous nucleoli, and indistinct cytoplasm, permeated by a large amount of collagen, sometimes thick. The arrows show the interface between the meningioma and brain parenchyma. C: Presence of psammomatous and other dystrophic pattern calcifications. Mitosis figures were not detected. D: An immunohistochemical study reveals epithelial membrane antigen expression. Original magnification ×40.

FIG. 3.

Postoperative MR images. A:Axial T1-weighted postgadolinium image. B:Sagittal T2-weighted FLAIR image revealing no residual tumor.