Constant ovulation during oral contraceptive treatment: Follicle-stimulating hormone-secreting pituitary adenoma case report and literature review.

Follicle-stimulating hormone (FSH)-producing pituitary neuroendocrine tumor is very rare and usually present with menstrual disorders, ovarian cysts, polycystic ovary morphology (PCOM), and so on. It is often confused with polycystic ovary syndrome (PCOS) and is difficult to diagnose. Missed or misdiagnosis may lead to unnecessary surgical injury or severe neurologic damage. We describe the case of a 37-year-old woman with persistent menstrual disturbances and ovarian cysts. Because of unceasing ovulation after usage of combined oral contraceptive (COC) she was suspected of having endogenous uncontrolled FSH and eventually a pituitary adenoma was found. In addition, we review the features of onset, diagnostic history, treatment, and prognosis of previous similar reports. We find the symptoms of FSH-secreting pituitary adenomas puzzling. Mild cases are easily overlooked, and severe cases are easily misdiagnosed as ovarian hyperstimulation syndrome and ovarian tumors and receive unnecessary pharmacological and surgical interventions. Attention to abnormal sex hormones is key to diagnosis, and prompt surgical tumor removal is important.