How is morphology of meningioma?

➢ Exhibit many different microscopic patterns. ➢ Most commonly the cells arrange in a tight, whorled pattern, with oval nuclei containing dispersed chromatin, giving them an open and vesicular appearance. ➢ They may also contain psammoma bodies or fibroblastic elements. ➢ Some meningiomas, particularly when multiple, occur with neurofibromatosis 2 ➢ Sporadic meningiomas often have a mutation involving the NF2 gene on the 22q chromosome. ➢ Atypical meningiomas have a higher mitotic index, increased cellularity, and increased nuclear tocytoplasmic ratio; (WHO grade II) ➢ they are associated with local invasion and increased risk for recurrence after resection. Meningiomas are uncommon in children. ➢Anaplastic (malignant) meningiomas (WHO grade III) are highly aggressive tumors that may resemble a high-grade sarcoma or carcinoma morphologically. ➢The female-male ratio is 3:2.