Mifepristone (RU486), a pure antiprogesterone drug, in combination with vinblastine for the treatment of progesterone receptor-positive desmoid tumor

We report the case of a patient who developed a desmoid tumor following total proctocolectomy and J-pouch reconstruction that was unresponsive to any medical treatment. Based on estrogen receptor alpha (ERα) and progesterone receptor (PR) evaluation (ERα-negative, but PR-positive), treatment with mifepristone, a pure antiprogesterone drug, was initiated, and partial tumor regression was achieved.