In vitro maturation (IVM) of oocytes retrieved ex vivo from ovarian tissue (OTO-IVM) could be an additional source of mature oocytes with the potential to optimise medical fertility preservation (FP) after oophorectomy. It is often undertaken at the same time as the ovarian tissue cryopreservation (OTC). In the presence of an organic ovarian cyst, OTO-IVM could prove to be the only technique available to permit FP since ovarian stimulation, transvaginal ovarian needle puncture or future ovarian tissue graft are contraindicated. However, the presence of an organic cyst could alter follicular growth and the number of retrievd oocytes. Our study aims to assess the efficiency of OTO-IVM in such situations.