Endocrine Abstracts

Introduction: The true prevalence of clinically relevant pituitary adenomas has been reevaluated at 1/1064 of the population (1). Among them, prolactinomas represent the majority with a prevalence of 1/2000. They occur usually in females, aged 20–50 Y.O., and 80% are microadenomas. Nearly 5% of prolactinomas appear in a familial or genetic setting (MEN-1 or FIPA) (2). Cabergoline is proposed as the first line therapy and is usually efficient to normalize prolactin (PRL) levels, restore fertility and shrink tumor volume.

Patients and methods: We screened the patients followed for prolactinomas in our endocrinology department from 1980 to 2020. We looked for epidemiological and radiological data, prolactin (PRL) levels, treatments, a familial setting, cancer, associated endocrine problems and pregnancy follow-up.

Results: The study population consisted of 303 females (76%, median age: 34,5 Y.O.) and 97 males (24%, median age: 42,3 Y.O.). Tumors were mainly micro-adenomas in women and macroadenomas in men. Median tumor size was 7 mm in females and 18 mm in males. PRL levels were lower in females (95,4 ng/ml vs 461,5 ng/ml) and correlated with tumor size. Main symptoms at diagnosis were amenorrhea and galactorrhea in women (80,1%). Men were complaining mainly of erectile dysfunction and/or loss of libido (44,3%) and headache (28,8%). A familial/genetic form was present in 16 patients (4%). These patients had bigger tumors. Overt or subclinical hypothyroidism occurred in 31,5% of our patients which is higher than the prevalence in comparable populations (3). Thyroid nodules were described in 22,5% of our patients. Breast cancer history was reported in 10 cases during follow up. Surgery was used in 38% of our patients, mainly before the year 2000; thereafter Cabergoline became the almost exclusive treatment. Under this medication, PRL levels were normalized in 80,6% of cases and a significant decrease of tumor size (>50%) was noted in 67,2% of cases (4). 98 pregnancies occurred, 73 under cabergoline. The later was stopped at the discovery of pregnancy, but had to be restarted before delivery in 8 cases. No fetal complications were reported.

Conclusions: Prolactinomas are a frequent cause of infertility in young women. Cabergoline is now the first choice therapy due to its efficiency and tolerability. Our data show the presence of three different populations of patients, with different biological and radiological presentations: males, females and familial cases. Anamnesis should query for genetic forms due to the early onset and high prevalence of macroadenoma. The prevalence of overt or subacute hypothyroidism raises the question whether patients with prolactinomas need to be systematically screened for thyroid function abnormalities. Finally, we did not have complications during pregnancy, in line with other reports from the literature (5).

References: 1. DalyA. F., Rixhon M., AdamC., Dempegioti A., Tichomirowa M.A., Beckers A. High prevalence of pituitary adenomas: A cross-sectional study in the province of Liege, Belgium. J Clin Endocrinol Metab. 2006;91:4769–75.

2. Barry S, Korbonits M. Update on the Genetics of Pituitary Tumors. Endocrinol Metab Clin NorthAm. 2020;49:433–452.

3. Elenkova A, Atanasova I, Kirilov G, Natchev E, Ivanova R, Kovatcheva R, Vandeva S, Tcharaktchiev D, Zacharieva S. Autoimmune hypothyroidism is three times more frequent in female prolactinoma patients compared to healthy women: data from a cross-sectional case-control study. Endocrine. 2017 Sep;57(3):486–493.

4 Vroonen L. et al. Prolactinomas resistant to standard doses of cabergoline: a multicenter study of 92 patients. Eur J Endocrinol. 2012 Nov;167(5):651-62.

5. Lebbe M., Hubinont C., Bernard P., Maiter D. Outcome of 100 pregnancies initiated under treatment with cabergoline in hyperprolactinaemic women. Clin Endocrinol (Oxf). 2010. Aug;73(2):236–42.