Atypical meningiomas represent 15% of meningiomas. They present a high rate of recurrence, and therapeutic strategies are limited. There is a need for novel treatment strategies, such as immuotherapy.

This is a retrospective study including 84 patients with primary diagnosis of atypical meningiomas. The presence of T cells (CD4, CD8, Treg and memory T cells) and mature dendritic cells will be quantified on whole tissue sections stained by immunohistochemistry (CD4, CD8, FOXP3, CD45RO and CD208).

This could allow us to identify novel biomarkers for survival, and facilitate the selection of patients who may benefit from immunotherapeutic modalities.

Inclusion Criteria:

• primary diagnosis of atypical meningioma
• surgery

Patients operated for a cerebral tumor, with primary diagnosis of atypical meningioma