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

Clear cell meningiomas-case presentation, review of radiographic identifiers, and treatment approaches

Spinal clear cell meningiomas (CCMs) are a rare histological subtype of meningiomas that pose preoperative diagnostic challenges due to their radiographic similarities with other lesions. They are also more aggressive, exhibiting higher rates of recurrence, particularly in pediatric patients. Overcoming diagnostic challenges of these tumors can improve patient outcomes. In this report, we describe a case of a pediatric patient presenting with a lumbar CCM in whom we were able to obtain gross total resection. Our report reviews previously identified predictors of CCM recurrence, including the Ki-67 proliferation index, number of spinal segments involved, and hormonal influences related to age and sex. We describe the characteristic radiographic features that differentiate spinal CCMs from other tumors to improve pre-operative diagnosis. Furthermore, we provide our rationale for adjuvant therapy for pediatric patients to refine treatment protocols for these rare tumors.

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.

Pituitary Adenoma Coexistent with Sellar Clear Cell Meningioma Unattached to the Dura: Case Report and Treatment Considerations

Collision tumors involving the sella are rare. Intrasellar collision tumors are most commonly composed of a combination of pituitary adenomas and pituitary neuroendocrine tumors; however, collision tumors consisting of a pituitary adenoma and intrasellar meningioma are exceedingly rare. The authors present the case of a 47-year-old man who presented with progressive right eye vision loss. Magnetic resonance imaging showed a large, heterogeneously enhancing sellar mass with suprasellar extension. Using a transcranial approach with a right subfrontal craniotomy, near-total resection of the mass was achieved. Histologic analysis confirmed a diagnosis of a gonadotroph adenoma with concomitant clear cell meningioma (CCM). This patient was discharged with improvement in visual acuity and no signs of diabetes insipidus. Given the indistinguishable radiographic characteristics of pituitary adenoma and CCM, a preoperative diagnosis of a collision tumor was difficult. This case was uniquely challenging since the CCM component lacked the classic dural attachment that is associated with meningiomas on neuroimaging. CCMs are classified as central nervous system (CNS) World Health Organization (WHO) grade 2 tumors and tend to behave more aggressively, therefore warranting close surveillance for signs of tumor recurrence. This is the first case to report a collision tumor consisting of pituitary adenoma and CCM.