Petroclival meningioma regression after combined oestrogen and nomegestrol acetate interruption

Meningioma regression after progestin treatment interruption is already established. Zoely is a combined oral contraceptive including oestradiol and progestin (nomegestrol acetate). The effect of combined oestrogen with nomegestrol acetate on meningioma is currently unknown. We report the case of a woman in her early 50s under Zoely for 5 years who was diagnosed with a large petroclival meningioma. After cessation of Zoely, the patient showed clinical improvement and shrinkage of the tumour volume from 27.22 cm³ to 20.54 cm³ in 6 months. This is probably the first report of spontaneous meningioma regression after Zoely interruption.