Pediatric Meningeal Tumors of the Sylvian Fissure Region without Dural Attachment: A Series of Three Patients and Review of the Literature

Abstract

Pediatric meningeal tumors are rare, but those in the region of the sylvian fissure without dural attachment are extremely rare, with only 24 previously reported cases in the world literature. In this series, we report two additional cases of sylvian fissure meningioma without dural attachment and one case of perisylvian meningioangiomatosis in the medial temporal lobe. All three patients presented with complex partial seizures, but the diagnosis was delayed in each case because the symptoms were misinterpreted to be behavioral rather than epileptic. The seizures were eventually confirmed with electroencephalogram, and subsequent imaging showed enhancing masses within the sylvian fissure region that were at least partially calcified in all three cases. Each patient underwent craniotomy. In the first case, gross total resection was achieved, and in the second case, a small residual portion of tumor was densely calcified and adherent to the middle cerebral artery branches. Both of these were World Health Organization (WHO) grade I meningiomas. The third patient underwent biopsy and limited resection of meningioangiomatosis. No dural attachments were noted in any of the tumors, but one of the meningiomas was intraparenchymal in location, surrounding the sylvian fissure in both the frontal and temporal lobes, which has been described in only a small number of these cases previously. The patients underwent pre- and postsurgical neuropsychiatric testing and did not experience any significant cognitive deficits. At 10-year follow-up, the patient who had gross total resection of the tumor has had no recurrence and is seizure-free without anticonvulsant medications. The incompletely resected intraparenchymal meningioma in the second patient recurred after 5 years, however, and at repeat surgery was found to have transformed to a WHO grade II tumor. Radiation therapy was delivered and the tumor has been stable for 2 years, but the patient continues to have occasional seizures despite medication. The patient with meningioangiomatosis has had no further growth and has excellent control of seizures but remains on medication. We review the clinical presentation of these rare tumors and discuss the treatment, outcomes, and possible relationship of meningiomas to meningioangiomatosis.

Keywords: meningeal tumors; pediatric tumors; seizures; sylvian fissure meningioma.

Fig. 1

(A) Coronal and (B) axial contrast-enhanced preoperative magnetic resonance imaging (MRI) for patient one showing uniformly enhancing mass measuring 5 × 5 × 4 cm within the left sylvian fissure region. (C) Coronal and (D) axial contrast-enhanced postoperative MRI for patient one showing postoperative changes after microdissection and successful resection of tumor with no significant residual enhancement along resection margins. There has been no delayed recurrence of tumor in this patient at 10 years' follow-up.

Fig. 2

(A) Axial, (B) coronal, and (C) sagittal contrast-enhanced preoperative magnetic resonance imaging (MRI) for patient two. A 4 × 5 × 4-cm homogeneously enhancing mass is present within the left sylvian fissure, which is densely calcified on noncontrast computed tomography (CT) (D). (E) Axial and (F) coronal contrast-enhanced postoperative MRI for patient two. Some residual tumor could not be safely resected at surgery because it was adherent to branches of the middle cerebral artery. (G) Coronal contrast-enhanced MRI and (H) noncontrast coronal CT for patient two, 5 years following incomplete resection, shows recurrence of the meningioma, with even more dense calcification. Histopathology following repeat surgery showed it had transformed to a World Health Organization grade II tumor.

Fig. 3

(A) Axial contrast-enhanced, (B) coronal contrast-enhanced, (C) coronal T2-weighted, and (D) axial noncontrast computed tomography preoperative images from patient three showing a partially calcified and minimally enhancing right medial temporal lobe/perisylvian mass. This result was concerning for a possible meningioma, but histopathology of the surgical specimen following right frontotemporal craniotomy and partial resection showed meningioangiomatosis.