Endocrine Abstracts

Introduction: Amenorrhea is a condition resulting from dysfunction of the hypothalamus, pituitary, ovaries, uterus, or vagina. Hyperprolactinemia is a relatively common endocrine disorder that produces amenorrhea by suppressing hypothalamic GnRH secretion. We describe a patient who had a Levonorgestrel intrauterine device (UID) since 5 years and who presented with amenorrhea in association with a macroprolactinoma.

Case report: A 45 year- old -woman presented for a routine gynecologic control. She had amenorrhea since an IUD was placed 5 years earlier. A routine blood test ordered by her gynecologist showed severe hyperprolactinemia (PRL 3298 microgram/l (4.8–23.3), accompanied by hypogonadotropic hypogonadism and hypothyroidism. IGF-1, ACTH and cortisol were normal. She was referred for further work up. She didn’t complain of headaches, visual disturbances or galactorrhea. On physical examination galactorrhea was found. The visual field was impaired, with superior left temporal hemianopsia. Additionally, a pituitary MRI scan showed a pituitary tumor with supra-seller extension (30 × 19× 25 mm) and compression of the left side of the chiasma opticum and deviation of the pituitary cleft to the right. Moreover a voluminous cavernoma lokated parietal paraventricul left with discrete mass effect on the corpus callosum was observed. Bone mineral density was normal. Treatment was initiated with 0.5 mg cabergoline 3 times a week and L-thyroxine. The monthly PRL concentration dropped as following to 568, 208, 52.9 (bioactive 43) and 31.1 (bioactive 27) ng/ml respectively. 6 months and 12 months later the prolactin bioactive was 27.8 and 9.5, respectively. Control MRI 1 year later showed regression (13 × 7mm) of the macro adenoma with lateralization to the left.

Discussion: The clinical manifestations of hyperproleactinemia in premenopausal women are oligo-or amenorrhea and infertility and are correlated with the magnitude of hyperprolactinemia. Less often galactorrhea occurs. Hyperprolactinemia accounts for 10 to 20% of cases of amenorrhea. Our patient presented with amenorrhea in association with a pituitary macroprolactinoma. Cabergoline treatment was effective in PRL normalization and regression of the macroprolactinoma. In this case, in the past, it was thought her amenorrhea was due to her hormonal IUD and hyperprolactinemia was not considered as a possible cause of amenorrhea and therefore had not been detected. Moreover, she had no other associated symptoms.

Conclusion: Clinicians should be aware that the amenorrhea associated with the IUD can hide a prolactinoma. Serum prolactin should be measured in every woman with amenorrhea.