Prolactinomas are the most prevalent pituitary adenomas. The incidence of prolactinomas varies with age and sex. The ratio between women and men has been estimated to 10:1 before the age of 50 years. Hypogonadism and infertility are important clinical problems associated with prolactinomas. There may be mass effects including visual field defects in a patient with a macroadenoma.
Hyperprolactinaemia is a relatively frequent finding in women. It is important to consider medication and primary myxoedema that may cause hyperprolactinaemia and, when appropriate, a pregnancy test must be performed. There are pitfalls regarding the biochemical diagnosis of hyperprolactinaemia. However, if hyperprolactinaemia is unequivocal, an MR-scan of the pituitary is indicated.
Prolactin is the most important acute blood sample in a patient with a pituitary adenoma and visual field defects. Because, generally, dopamine-agonists are first-line therapy for prolactinomas. Cabergoline, bromocriptine and quinagolide are the dopamine-agonists, we use. We want to normalize prolactin levels to obtain eugonadism and we aim at reducing tumour size. Surgery and radiotherapy may be used for the few resistant prolactinomas.
When fertility is an issue, the woman has to be informed about the possible risks of prolactinoma growth during pregnancy and we have to consider which dopamine-agonist should be chosen. In all patients the safety of dopamine-agonists is important. During the last 5 years, there have been reports on cabergoline and the risk of valvular heart disease. The authorities have requested that patients on cabergoline are referred to echocardiography follow-up. There are ongoing studies trying to elucidate the risk of heart disease in patients with prolactinomas. Dopamine-agonist withdrawal may be considered in patients who achieve normoprolactinemia and complete tumour disappearance. Patients with prolactinomas and hypopituitarism should receive standard hormone replacement therapy. However, gonadal replacement should be delayed. An assessment of the bone mineral density (BMD) is generally indicated.
Declaration of interest: The author declares that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.