Microsurgical excision of multiple clear cell meningiomas of the cauda equina: a case report

Central nervous system clear cell meningioma: a systematic literature review

Clear cell meningiomas are a rare histological subtype of World Health Organization (WHO) grade II meningioma. Despite its relatively low frequency, clear cell meningioma has attracted considerable attention because of its unique pathological characteristics, clinical behavior, and challenging management considerations. The purpose of our systematic review is to provide clinicians with a better understanding of this rare disease. PubMed was searched for articles in the English language published from 1988 to 2023 June. The keywords were as follows: "clear cell meningioma," "clear cell" and "meningioma." We analyzed clinical manifestations, radiological manifestations, pathological features, comprehensive treatment strategies, and prognosis to determine the factors influencing recurrence-free survival (RFS). Recurrence-free survival curves of related factors were calculated by the Kaplan‒Meier method. The log-rank test and Cox univariate analysis were adopted to assess the intergroup differences and seek significant factors influencing prognosis and recurrence. Fifty-seven papers met the eligibility criteria, including 207 cases of clear cell meningioma (CCM), which were confirmed by postoperative pathology. The fifty-seven articles involved 84 (40.6%) males and 123 (59.4%) females. The average age at diagnosis was 27.9 years (range, 14 months to 84 years). Among the symptoms observed, headache, neurologic deficit, and hearing loss were the most commonly reported clinical manifestations. Most tumors (47.8%) were located in the skull base region. Most tumors showed significant enhancement, and homogeneous enhancement was more common. A total of 152 (74.1%) patients underwent gross total resection (GTR), and 53 (25.9%) patients underwent subtotal resection (STR). During the follow-up, the tumor recurred in 80 (39.4%) patients. The log-rank test and the Cox univariate analysis revealed that tumor resection range (GTR vs. STR) and adjuvant treatment (YES vs. NO) were significant predictors of recurrence-free survival (RFS). Clear cell meningioma is a rare type of meningioma with challenging diagnosis and therapy. The prognosis of this disease is different from that of regular meningiomas. Recurrence remains a possibility even after total tumor resection. We found that the surgical resection range and adjuvant treatment affected the recurrence period. This finding provides significant guidance for the treatment of clear cell meningioma.

Intraspinal clear cell meningioma without dural attachment: A case report and literature review

RATIONALE

Clear cell meningioma (CCM) is one of the rarest but most aggressive forms of meningioma, with a tendency to occur at a high recurrence rate. Intraspinal CCM, especially the nondura-based type, is even rarer than the intracranial CCM.

PATIENT CONCERNS

We report a case of a 45-year-old woman who presented with a 1-month history of episodic pain in the lower back and in both thighs in the front side. Femoral nerve stretch tests were positive on both sides. Magnetic resonance imaging (MRI) demonstrated an intradural tumor at the L3 level, which was isointense on T1- and T2-weighted images (WI) and homogeneously enhanced on gadolinium-contrast T1 WI.

DIAGNOSES

The space-occupying lesion was pathologically confirmed as CCM.

INTERVENTIONS

During surgery, we found that the tumor adhered to a nerve root, without dural attachment. The nerve root was partially removed to achieve complete resection.

OUTCOMES

The pain disappeared after the operation. The 1 year follow-up MRI revealed no evidence of tumor recurrence or metastasis.

LESSONS

Nondura-based intraspinal CCM is easier to completely remove, and such complete removal should be achieved during the first operation. Although the recurrence rate of this particular type of meningioma appears to be lower than that of other types, close clinical and radiological follow-up is necessary.

Intraoperative Anatomical Findings in Pediatric Clear Cell Meningioma of the Lumbar Spine: Case Report and Literature Review

Clear cell meningioma (CCM) is a WHO classification Grade II meningioma. It is a very rare disease, of which only 41 cases of spinal cord CCM in children have been reported to date. CCMs sometimes do not have the “dural attachment” that is usually found in meningiomas, and our understanding of the origin of CCMs is therefore controversial. We hereby present a case of pediatric CCM of the lumbar spine, in which we examined intraoperatively, the detailed anatomical location of the tumor. The case is a 10-year-old boy, who presented to our hospital with a 2-month history of lower back and bilateral lower extremity pain upon waking, which gradually worsened. Lumbar spine CT and MRI revealed an intradural extramedullary tumor at the L3 vertebral level, and surgery was performed to remove it. The tumor was in close contact with the dura mater, and also in contact with the cauda equina via the arachnoid. The tumor was likely located primarily between the dura mater and arachnoid. The pathological diagnosis was CCM, with an MIB-1 index of less than 1%. His back pain and bilateral lower extremity pain improved after surgery, and he was discharged from our hospital. Postoperative radiation therapy was not performed. Based on this case, we suggest that intraoperative examination of the anatomical location of these tumors and accumulation of relevant experience are important to elucidate the embryological mechanisms of this rare disease.

Spinal Clear Cell Meningiomas: Clinical Features and Factors Predicting Recurrence

OBJECTIVE

As a World Health Organization grade II tumor of the nervous system, clear cell meningioma (CCM) is an uncommon histologic variant of meningioma. Spinal CCMs are even rarer, with <100 spinal CCMs reported in the English literature. We present this study to characterize clinical manifestations of spinal CCMs and determine the factors predicting recurrence.

METHODS

A literature search was performed for relevant case reports and series in PubMed and Embase until September 1, 2019. These articles were reviewed to identify clinical features, treatment modalities, and prognosis of patients with spinal CCMs.

RESULTS

Eighty-four spinal CCMs were analyzed. Of these patients, 36 (42.9%) were young (age ≤18 years), and the mean age at resection was 24 years. Fifty-three patients (63.1%) were female and 31 (36.9%) were male. Most of the tumors (56/84, 66.7%) were located in the lumbar region. In 31 patients (36.9%) >2 segments in the craniocaudal direction were involved (number of involved segments ≥3 levels). Gross tumor resection was performed in 77 patients (91.7%). Twenty patients (23.8%) showed radiographic evidence of recurrence during follow-up. Recurrence-free survival at 1, 5, and 10 years after resection of spinal CCM was 87%, 71%, and 47%, respectively. Multivariate analysis showed that age ≤18 years (hazard ratio [HR], 3.64; P = 0.024), subtotal resection (HR, 3.43; P = 0.031), and segments involving ≥3 levels (HR, 5.66; P = 0.002) were associated with increased recurrence.

CONCLUSIONS

Spinal CCMs have their own unique clinical features compared with conventional spinal meningiomas and intracranial CCMs. Spinal CCMs have a predilection to affect younger patients, are prone to appear in the lumbar region, and have a high recurrence rate. Age ≤18 years, subtotal resection, and involvement of long segments (≥3 levels) are positive predictors of recurrence.

Non-dural-based spinal meningioma : the first case report of a fibrous subtype and a review of the literature

Spinal meningiomas typically adhere to the dura matter. Non-dural based spinal meningiomas are rare and most are clear cell meningiomas. We report here the first case of a fibrous meningioma with non-dural attachment. The patient was a 49-year-old female, who complained of numbness in the legs and a gait disturbance. Magnetic resonance imaging revealed a 1.7×1.4-cm mass in the C7-T1 intra-dural extramedullary space, showing peripheral gadolinium enhancement without a "dural tail sign". A complete microsurgical resection was performed. The mass was covered with a white membrane but was not adhered to the dura, and its appearance was consistent with a neurilemmoma. The histopathological diagnosis was fibrous-type meningioma. The recovery of the patient was uneventful. No surgical complications and no recurrence of the tumor had occurred at the 6-month follow-up.

Spinal clear cell meningioma in a 3-year-old: a case report

Clear cell meningioma (CCM) is an aggressive meningioma variant with a tendency to early recurrence posing a challenge to its treatment. Although spinal meningiomas are uncommon in children, this rare entity has been described as the most common variant of spinal meningiomas in the pediatric age group. We present the case of a 3-year-old with a confirmed lumbar spine CCM and discuss the problems encountered in the management of this disease.