Pitfalls in the Histopathologic Diagnosis of Meningioma: Report of Three Rare Variants of Meningioma and Literature Review

Meningioma is a common primary tumor of the central nervous system and one of the most encountered brain tumors. Although classic histopathologic features of meningioma are relatively common and make its diagnosis straightforward, certain variants possess unusual histologic features causing diagnostic challenges. We reported three cases of clear cell meningioma, microcytic meningioma, and angiomatous meningioma report, variants with potential deceptive morphologies, and discuss their distinguishing morphologic features.

Clear cell meningioma in a child: Case report and systematic literature review

Antecedentes: El meningioma de células claras (MCC) consiste en una variante poco común de meningiomas que generalmente ocurren en niños. Este tumor poco común se comporta de manera agresiva y las tasas de recurrencia son altas. Las manifestaciones clínicas son atípicas y el tratamiento generalmente implica cirugía. Métodos y Objetivos: Realizamos una revisión sistemática con el fin de definir las características más comunes de este raro tumor. Pubmed y LILACS fueron las bases de datos utilizadas para la búsqueda bibliográfica. Se incluyeron 17 estudios que cumplieron con nuestros criterios. Para avanzar en nuestra investigación, incluimos el caso clínico de una niña de 3 años con CCM operada en nuestro servicio. Resultados: Los MCC fueron más frecuentes en la población pediátrica que en la adulta, especialmente en el sexo femenino. La resección macroscópica del tumor y el índice MIB-1 < 3 fueron los parámetros relacionados con una menor tasa de recurrencia. La resección subtotal del tumor fue seguida de radioterapia en la mayoría de los casos de adultos. La mutación SMARCE-1 se pudo encontrar en varios pacientes. Conclusión: Los MCC son meningiomas raros que ocurren especialmente en niños. La agresividad y las altas tasas de recurrencia dificultan el manejo de esta enfermedad. Aún queda mucho por discutir sobre estos tumores raros, lo que exige más investigación.

Spinal Clear Cell Meningioma: Atypical Clinical and Radiological Manifestations

Meningioma has many subtypes with clear cell meningioma being more aggressive than other variants of meningioma and one of the rarest. We report a case of spinal clear cell meningioma that occurred in a 25-year-old lady who presented with the inability to be in the supine position. A magnetic resonance image showed an intradural mass extending from L1 to L4. Near complete excision was done. The patient had motor weakness postoperatively which improved gradually. A histopathological study showed a clear cell meningioma. In a differential diagnosis of any space-occupying lesion of the spine, clear cell meningioma should be considered though it is a rare form of meningioma due to its potential to recure. An accurate follow-up is warranted.

Venous Anatomy Influence on the Approach Selection of a Petroclival Clear Cell Meningioma With Associated Multiple Spinal Meningiomas: 2-Dimensional Operative Video

Preoperative careful evaluation of the sigmoid transverse sinus and its tributary veins is paramount for the safe surgical planning of petroclival lesions.1,2 When the vein of Labbé is running within the tentorium, classic petrosal approach involving transection of the tentorium is modified to avoid the risk of postoperative morbid temporal lobe venous infarcts.1-3 Thus, the surgical plan should be tailored to the specific patient anatomy as demonstrated in the presented case during which a transmastoid approach was followed, in the same surgical setting, by a middle fossa approach to resect a large petroclival clear cell meningioma with extension into Meckel cave. These meningiomas are WHO grade II tumors with a propensity to local recurrence and cerebrospinal fluid seeding.4 SMARCE1 mutations define this subtype of meningioma, with frequent familial inheritance, and predispose patients to both skull base and spinal clear cell meningiomas.5,6 Maximal surgical resection is the best initial treatment option allowing to withhold or delay the use of radiation in tumors frequently encountered in young patients.7 In this report, we demonstrate the microsurgical techniques deployed to achieve maximal resection of a petroclival clear cell meningioma and associated lumbar and sacral spinal meningiomas in a 20-yr-old patient with a familial SMARCE1 mutation. The patient agreed to the surgical intervention and to the use of her image.

Clear Cell Meningioma in the Central Nervous System: Analysis of Surveillance, Epidemiology, and End Results Database

BackgroundClear cell meningioma (CCM) is a rare subtype of meningioma, accounting for approximately 0.2% of all meningiomas. The present study aimed to analyze the epidemiology and outcome of CCMs using the Surveillance, Epidemiology, and End Results (SEER) database.MethodsPatients diagnosed with central nervous system CCM between 2004 and 2016 were identified from the SEER database. Descriptive analyses were performed to evaluate the distribution of patients and tumor-related characteristics. The survival analysis was performed using Kaplan-Meier curves. The Cox proportional hazards model was used for the univariate and multivariate analyses.ResultsThe age-adjusted incidence rate was 0.032 per 1,000,000 person-years. The median age was 52 years. Most of the CCMs were intracranial CCMs that were larger than 3 cm. The overall cumulative survival rates at 1, 3, and 5 years were 97.6, 93.2, and 86.9%, respectively. The log‐rank test and Cox proportional hazards regression analysis revealed that age at diagnosis and primary site of the tumor were independent prognostic factors.ConclusionCCM is an extremely rare entity with a favorable survival rate. CCMs usually affect patients during the fourth to fifth decades of life. Patients diagnosed at 21–60 years old and patients with spinal CCMs have a better prognosis.