RESUMO
Amenorrhea is a clinical condition characterized by failure of menarche or by the absence of menstruation for six months in a woman with previous periodic menses. We report a first case of a 30 year-old woman affected by polycystic ovarian disease (PCOD) whose amenorrhea ceased after a 6-month combination treatment with cyclic estradiol-norethisterone acetate. After the withdrawal of the hormone therapy, a stable recovery of periodic menses was observed. We describe a second case of a 23 year-old woman whose amenorrhea was caused by a hypogonadotropic hypogonadism due to a non-functioning pituitary adenoma. After the administration of the previously described therapy both a disappearance of the adenoma and a recover of periodic menses were observed. We hypothesized that the outcomes in our cases could be the consequence of a balancing action induced by the exogenous hormone administration. The exogenous hormones may have reset the feedback between the hypothalamus and pituitary gland through mimicking the physiological hormones pattern of the 28-day cycle.