The authors reported 2 cases of functioning gonadotroph pituitary adenoma (FGPA) revealed by an ovarian hyperstimulation syndrome (OHSS) in young women. In the first case, OHSS was observed after GnRH analog injection. Pelvic echography revealed multiple voluminous ovarian cysts. Dopamine agonist posology failed in estradiol hypersecretion control, which necessitated endoscopic endonasal transsphenoidal surgery. The patient experienced improvement in pelvic pain as estradiol hypersecretion decreased during the first few postoperative days. Outcome was favorable, and her menstrual cycle was normal after two months. The second case was a young girl with spontaneous pelvic pain and elevated plasma FSH and estradiol levels. FGPA was confirmed on cerebral MRI. Dopamine agonists were introduced, and surgical removal of the pituitary tumor was scheduled for 7 days later. In the meantime, the patient was admitted and underwent surgery for bilateral adnexal torsion related to OHSS. The pituitary tumor was removed one week later. Outcome was favorable, and estradiol and FSH plasma levels were normal after 3 months. The ovarian cysts were no longer visible on echography after 3 months. Given the lack of efficacy of the current standard medical therapy, surgical removal of pituitary adenomas is the reference treatment for FGPA. The authors suggest that severe OHSS related to FGPA should be considered as a relative surgical emergency and that surgery should not be unduly delayed, given the unpredictable risk of adnexal torsion, particularly in case of voluminous ovarian cysts. The authors performed a literature review on this topic. (C) 2019 Elsevier Masson SAS. All rights reserved.