RESUMEN
BACKGROUND: Long-term use of high-dose progestin is known to promote the development of meningioma. Atypical meningioma in a patient under progestin has not previously been reported. CASE REPORT: A 53-year-old right-handed woman presented with focal onset seizures, without impaired consciousness. Medical history featured endometriosis, treated successively by cyproterone acetate 25mg/day for 2 months then 50mg/day for 101 months, and chlormadinone acetate 5mg/day for 68 months then 10mg/day for 83 months. Brain MRI revealed multiple extra-axial lesions suggestive of left central meningioma associated with anterior skull base meningiomatosis. Surgical resection of the left central meningioma was achieved and progestin was withdrawn. Neuropathology diagnosed grade II atypical meningioma. Close clinical and imaging monitoring was implemented without adjuvant oncological treatment. At 25 months, imaging follow-up showed no recurrence of the left central meningioma and a significant regression of all other lesions, except for the right frontal lesion. CONCLUSIONS: Neurosurgeons should be aware of the possible aggressiveness of meningioma in patients under progestin, and particularly those treated by different types of progestin over a long period of time without interruption. This may require systematic close monitoring, to adapt neurosurgical management.