Pediatric Fourth Ventricular Atypical Meningioma With a Whorling-Sclerosing Pattern: A Report of a Rare Tumor.

Meningiomas are rare in the pediatric age group and also very rare in the fourth ventricle. We describe a report of an 11-year-old boy who presented with frequent involuntary movements and an imbalance while walking. His MRI scan showed a well-defined T2 and FLAIR hyperintense lesion in the fourth ventricle, suspected to be a medulloblastoma. Post-excision of the tumor, histology showed a brain invasive atypical meningioma with a peculiar whorling-sclerosing architecture. The tumor cells were positive for EMA, PR, SSTR2A and showed retained MTAP and H3k27me3 expression. The MKI67 index was 8% to 10%. The tumor was negative for a CDKN2A/B homozygous deletion and a TERT promoter mutation. Post-surgery, the patient showed immediate improvement in symptoms and was asymptomatic at the time of discharge and follow-up.