[Membranous dysmenorrhea or passage of a decidual cast - forgotten phenomenon but not rare? Case report and summary of the literature].

Membranous dysmenorrhoea is present when the decidualized endometrium sheds in one piece, a decidual cast, which remains the shape of the uterine cavity. It has often been associated with initiation or cessation of hormonal treatments. Cases with extrauterine pregnancy, miscarriage, abortion, pregnancy in uterus didelphys/bicornis, and following post partum haemorrhage, as well as a few spontaneous cases, have also been described. We report a case of a 24-year old woman who started oral contraceptive pills three months previously. She presented with abdominal pain and vaginal bleeding. During examination membranous tissue was found, a pregnancy test was negative, and histology revealed decidualized endometrium. Further, we discuss clinical management and possible etiologic pathways suggesting that matrix-metalloproteinases or their regulators are involved.