Multiple ovarian cysts and oligomenorrhea as the initial manifestations of a gonadotropin-secreting pituitary macroadenoma.

Objective: To report a case of a follicle-stimulating hormone (FSH)-secreting pituitary adenoma, which manifested with oligomenorrhea, dysmenorrhea, and multiple bilateral ovarian cysts.

Methods: We present a case report of a 29-year-old woman, including detailed laboratory, radiologic, and pathologic findings, who was diagnosed as having an FSH-secreting pituitary tumor. The pertinent literature is also reviewed.

Results: A 29-year-old woman, after experiencing oligomenorrhea and increasing abdominal girth for >1 year, presented with an acute abdomen. Ultrasonography revealed multicystic ovaries >15 cm in maximal diameter, causing bilateral adnexal torsion. After bilateral ovarian cystectomies, ultrasound study showed recurrence of the cysts. Relevant laboratory data were as follows: serum FSH 6.8 mIU/mL, luteinizing hormone 0.1 mIU/mL, prolactin 67 ng/mL, human chorionic gonadotropin <2 mIU/mL, progesterone 3.5 ng/dL, estradiol 237 pg/mL, thyrotropin 1.8 microIU/mL, testosterone <4 ng/dL, insulin 8.0 microIU/mL, and fasting plasma glucose 87 mg/dL. Magnetic resonance imaging (MRI) of the brain revealed a 2.5-cm pituitary mass, although the patient had no symptoms of pituitary dysfunction. Transsphenoidal removal of the mass was performed, and pathology studies were positive for FSH-secreting adenoma. Repeated MRI at 3 months showed an 0.8-cm residual tumor. The patient refused adjuvant radiotherapy. Regular menses resumed within 2 months postoperatively, and she later successfully became pregnant. Almost 3 years after treatment, the patient remained asymptomatic, results of pituitary function tests were normal, and follow-up MRI showed no signs of tumor regrowth.

Conclusion: Although very uncommon, gonadotropin-secreting pituitary adenomas should be considered in the differential diagnosis of new-onset oligomenorrhea and dysmenorrhea, especially if associated with multicystic ovaries on ultrasound study, even in the absence of elevated levels of serum gonadotropins. Furthermore, we propose that it may be acceptable to withhold adjuvant radiotherapy in patients who are asymptomatic after transsphenoidal surgical excision of these tumors.