Primary intraparenchymal meningiomas are rare but are more frequent in males than in females in children. This difference may be associated with increased estrogen levels in adult women and increased susceptibility to meningiomas. Female cases are extremely rare; to date, there are only 6 cases, including ours, and most of them have occurred in the cerebral lobes The most common location was the frontal lobe (n=2, 33.3%) and temporal lobe (n=2, 33.3%), followed by the parietal lobe (n=1, 16.7%) and brainstem (n=1, 16.7%). Presenting symptoms depend on tumor location, and seizures (n=4) were most frequent. One case had hemiplegia because the tumor was located in the brainstem. Another case was characterized by vomiting and microcephaly because the tumor was giant. The CT(Computerized Tomography) scan of the head showed a 9.5-cm calcified cystic mass in the left frontal region.
In general, most meningiomas are grade I, accounting for 80%–90%, whereas 5%–15% are grade II and 1%–3% are grade III[22, 23]. The meningothelial type is the most common, followed by the fibrous type. Among intraparenchymal meningiomas in children, the most common meningiomas are grade I (n=12, 66.7%), and the most common type is fibrous (including fibrous components) (n=8). There were 6 grade II and grade III cases, accounting for 33.7%. At present, the cases of female children are extremely rare. Only 4 cases had definite pathological results, which included fibrous (n=2), anaplastic (n=1), and clear cell (n=1). The present case is the first case of fibrous intraparenchymal meningiomas located in the temporal lobe in female children. Among 12 cases of children, homogeneous enhancement (n=6), fibrous (n=3), and meningothelial (n=1) were noted; none of the remaining cases had clear pathological reports. Heterogeneous enhancement (n=6), atypical (n=2), anaplastic (n=1), fibrous (n=1), clear cell (n=1), and transitional (n=1) were also reported. The present cases were fibrous and showed homogeneous enhancement, including ours; 4/5 fibrous intraparenchymal meningiomas showed homogenous enhancement.
Since intraparenchymal meningioma lacks dural attachment, characteristics such as cyst formation and the presence of peritumoral edema are relatively common in childhood. Moreover, it is often difficult to preoperatively distinguish it from gliomas, cavernous angiomas, metastatic tumors, malignant lymphomas, or sarcomatous lesions. Among 20 cases, cysts were found in 6 cases, and peritumoral edema was found in 9 cases. Especially when cystic components are present, it is more difficult to correctly diagnose these lesions because cysts are often associated with gliomas or metastatic tumors and are rarer among meningiomas. Peritumoral edema of intraparenchymal meningioma surrounding the lesion develops strongly in the region where the lesion is attached to the surrounding brain tissue, whereas peritumoral edema of most gliomas or metastatic tumors tends to surround the entire tumor surface. Wada et al. believe that the feature of any peritumoral edema of intraparenchymal meningiomas can help differentiate between intraparenchymal meningiomas and high-grade gliomas or metastatic tumors However, its characterization is not applicable to all intraparenchymal meningiomas. Peritumoral edema surrounding the entire tumor surface was found in 3 of 9 cases[10, 12, 20]. Hence, the radiological features of most pediatric primary intraparenchymal meningiomas, such as cystic components, peritumoral edema surrounding the entire tumor, and no dural tail sign, make accurate preoperative diagnosis extremely difficult.
Almost all intraparenchymal meningiomas were located in the cerebrum and lacked dural attachment and no association with the dura of the skull base or the sinuses. Only 3 of 20 cases in children underwent subtotal resection. For lesions located in the hemisphere, one patient underwent STR(subtotal resection), but the reason was not stated. In one case, STR was performed because of the rich blood supply, tight adhesion with the ACA(anterior cerebral artery) and lower tolerance of blood loss in children. There was a 70% remnant in one patient because of the lesion in the brainstem. No recurrences occurred in any patients who underwent total tumor resection during the follow-up period (15 weeks-5 years). Postoperative radiotherapy is controversial for children. Some reports have shown the development of meningiomas after high-dose irradiation with long latency periods[26, 27]. Gosztonyi et al.  believe that low-dose irradiation also causes the development of meningiomas with long latency periods in children. Some people treated patients with malignant meningiomas, and radiotherapy was used in the postoperative course. But, Ghim, TT et al.believe that high-dose radiotherapy should be avoided in the treatment of meningiomas in children. Some studies showed that the extent of initial surgical resection was the strongest independent prognostic factor for pediatric meningiomas and that upfront radiotherapy achieved no benefit[29, 30]. Hence, surgery is the best modality of treatment, and resection is recommended to achieve maximum extirpation.
Some authors thought that intraparenchymal meningiomas arise from arachnoid cells located within the pia mater and enter the surface of the brain or sulcus with perforating blood vessels[7, 24, 25][8, 25, 26]. Several cases involved the MCA(middle cerebral artery) branches or had feeding arteries of the MCA in children[6, 12, 17]. A patient's tumor is closely related to the perforating arteries of the ACA and middle cerebral artery and the recurrent artery of Heubner. In one case, several small arteries were found to enter into the lesion. These cases provide better support for the establishment of this theory. Therefore, for patients suspected to be intraparenchymal meningiomas and for whom the tumor is located in the blood supply range of the ICA(internal carotid artery), MRA(MR Angiography) or CTA(CT angiography) should be performed to evaluate the relationship between the tumor and blood vessels before the operation. During surgery, we should pay attention to the protection of blood vessels to avoid the neurological dysfunction caused by cerebral infarction after surgery, such as hemiplegia and aphasia. Our patient’s preoperative CTA showed that the lesion appeared intimately connected to proximal MCA branches. During the operation, the temporal branch of the m2 segment of the middle cerebral artery was found to be involved in the blood supply of the tumor.
We present an extremely unusual case of intraparenchymal fibrous meningioma of the temporal lobe with peritumoral and review the pertinent literature. Imaging features such as cystic degeneration, peritumoral edema, and absence of meningeal tail signs make accurate preoperative diagnosis difficult. However, most patients can achieve total resection and a good prognosis.