P13.12.A WHICH MENINGIOMA MANAGEMENT TO PLAN A PREGNANCY? PER PREGNANCY MENINGIOMA GROWTH STUDY AND NEUROPATHOLOGICAL CONSIDERATIONS

Abstract BACKGROUND Meningiomas are the most frequent intracranial tumors in adult particularly in woman. They are known to potentially increase in size during pregnancy occasionally requiring surgical removal mostly when located close to the optic pathways. Nevertheless, meningioma increase in size during pregnancy remains poorly studied and poorly predictable. Literature data on meningioma growth during pregnancy are particularly scarce. High progesterone blood level during pregnancy combined with high progesterone receptor (PR) expression of the tumor are strongly suspected to be involved in meningioma growth during pregnancy. In the present study, we first aimed to analyze meningiomas neuropathology and PR expression in the general population of young women, then we measured meningioma growth during pregnancy with neuropathological implication. MATERIAL AND METHODS We retrospectively analyzed the neuropathology of 112 operated on meningiomas in women from 18 to 45 years old. Then, we retrospectively perfomed volumetric analyses of meningiomas before, during and after pregnancy. RESULTS Among 112 analyzed meningiomas, 100% (39/39) skull base meningiomas strongly express PR. PR expression was more variable for convexity and posterior fossa meningiomas. 86% (96/112) were WHO grade 1. Nine volume measurements were performed during pregnancy in 6 women with a 3D volume increase varying from +68%, +204%, +467%, +61% and +75% in one patient with 2 pregnancies,,+244% and +498% in another patient with 2 pregnancies, +593% and + 0% in one patient who underwent a radiosurgery before the second pregnancy. Despite various per pregnancy growth, all were WHO grade 1 meningiomas. Four were located in the skull base, one in the convexity and one in the posterior fossa. All these meningiomas highly expressed progesterone receptors. Moderate decrease in tumor volume after delivery was observed in one case. CONCLUSION These results highlight the very important meningioma growth during pregnancy, which was not clearly reported in the literature. Based on these data, radical treatment is clearly required before pregnancy for meningiomas located close to fragile structures, particularly optic nerves. Most meningiomas strongly express progesterone receptors, including 100% of the skull base ones, suggesting that meningioma increase in size during pregnancy is highly probable for each case. These results suggest a multidisciplinary meningioma management in order to plan safely a pregnancy.