Follicle stimulating hormone-secreting pituitary microadenoma with fluctuating levels of ovarian hyperstimulation

BACKGROUND: Enlarged multicystic ovaries and an elevated estradiol (E2) concentration have been reported as characteristics of follicle stimulating hormone (FSH)-secreting adenomas in reproductive-aged women. The natural course of the hormone in relationship to the microadenoma and ovarian findings, however, remains largely unknown. CASE: A 40-year-old woman with enlarged multicystic ovaries was nonsurgically diagnosed with an FSH-producing pituitary microadenoma. During her subsequent 12-month follow-up, the serum concentration of E2, but not FSH, and the size of the multicystic ovaries fluctuated dramatically. Both the E2 level and ovarian size were transiently normalized. CONCLUSION: Because of disease-related fluctuations, a reproductive-aged woman with an FSH-producing adenoma did not always present with laboratory values characteristic of ovarian hyperstimulation. This finding points out a possible pitfall in diagnosis and clinical management.