ABSTRACT Objective Determining the etiology of hyperprolactinemia is fundamental for selecting the most appropriate treatment strategy. The aim of this study was to evaluate the usefulness and accuracy of prolactin levels in predicting the etiology of nonphysiological hyperprolactinemia. Subjects and methods In this retrospective study, we reviewed medical records of patients with nonphysiological hyperprolactinemia seen at two neuroendocrine reference centers located in Recife, Brazil, from January 2000 to December 2019. Results The study included 770 patients aged 12-73 years (65% […]

ABSTRACT Hyperprolactinemia is a frequent cause of menstrual irregularity, galactorrhea, hypogonadism, and infertility. The most common etiologies of hyperprolactinemia can be classified as physiological, pharmacological, and pathological. Among pathological conditions, it is essential to distinguish prolactinomas from other tumors and pituitary lesions presenting with hyperprolactinemia due to pituitary stalk disconnection. Proper investigation considering clinical data, laboratory tests, and, if necessary, imaging evaluation, is important to identify the correct cause of hyperprolactinemia and manage the patient properly. This position statement by […]

ABSTRACT Prolactinomas are the most common pituitary adenomas (approximately 40% of cases), and they represent an important cause of hypogonadism and infertility in both sexes. The magnitude of prolactin (PRL) elevation can be useful in determining the etiology of hyperprolactinemia. Indeed, PRL levels > 250 ng/mL are highly suggestive of the presence of a prolactinoma. In contrast, most patients with stalk dysfunction, drug-induced hyperprolactinemia or systemic diseases present with PRL levels < 100 ng/mL. However, exceptions to these rules are […]

Prolactinomas are the most common pituitary adenomas that affect young women at fertile age. Hyperprolactinemia causes hypogonadism, menstrual irregularities or amenorrhea in women, low serum testosterone levels in men, and infertility and sexual dysfunction in both men and women. Macroprolactinomas may cause cephalea, visual disturbance, and hypopituitarism. Clinical treatment with dopamine agonists is the gold standard, with cabergoline as the first choice due to its greater efficiency and tolerability. In about 20% of the cases, treatment is partially or completely […]

The definition of the etiology of hyperprolactinemia often represents a great challenge and an accurate diagnosis is paramount before treatment. Although prolactin levels > 200-250 ng/mL are highly suggestive of prolactinomas, they can occasionally be found in other conditions. Moreover, as much as 25% of patients with microprolactinomas may present prolactin levels < 100 ng/mL, which are found in most patients with pseudoprolactinomas, drug-induced hyperprolactinemia, or systemic diseases. On the other hand, some conditions may lead to falsely low PRL […]

Objective : To establish whether there is a relationship between hyperprolactinemia and primary thyroid disorders, focusing on patients with autoimmune features. Materials and methods : The medical records of 100 patients with hyperprolactinemia (HPRL) were retrospectively examined. Records of thyroid ultrasonography (USG), basal serum levels of thyroid stimulating hormone, circulating free thyroxine, free triiodothyronine, antithyroglobulin (anti-Tg), and antithyroperoxidase (anti-TPO) antibodies were analyzed. In 100 control subjects, matched by age and gender with HPRL patients, thyroid USG, thyroid function tests (TFTs), […]

Sellar and parasellar masses blocking inhibitory hypothalamic dopaminergic tonus can produce hyperprolactinemia. One of these conditions, seldom reported, is internal carotid artery aneurysm causing pituitary stalk compression and hyperprolactinemia, the majority of which is related to small increases in serum prolactin levels. The aim of this study is to report the case of a patient with an internal carotid aneurysm and severe hiperprolactinemia. A 72 years old female patient, on oncology follow-up for clinically controlled cervical carcinoma, was evaluated due […]

Macroprolactinemia is characterized by the predominance in the serum of macroprolactin, a prolactin (PRL) with high molecular mass and low biological activity that does not need treatment. The prevalence of macroprolactinemia was evaluated in 115 consecutive patients with hyperprolactinemia. Among them, 19 (16.5%) had solely macroprolactinemia, 4 (3.5%) polycystic ovary syndrome, 7 (6.1%) acromegaly, 8 (6.9%) idiopathic hyperprolactinemia, 10 (8.6%) primary hypothyroidism, 14 (12.2%) clinically non-functioning pituitary adenomas, 20 (17.4%) drug-induced hyperprolactinemia and 33 (28.7%) prolactinomas. The diagnosis of macroprolactinemia […]

Long term use of high doses of estrogen and the presence of chronic hyperprolactinemia may, at least in the rat, provoke lesions in the tuberoinfundibular dopaminergic (TIDA) neurons responsible for the control of prolactin (Prl) secretion. This occurrence, which is not yet well documented in humans, may have taken place in a patient on chronic oral hormonal contraceptive (OC) treatment who was seen for primary hypothyroidism, hyperprolactinemia and a pituitary mass. After thyroid hormone replacement, OC withdrawn and bromocriptine treatment, […]

In the diagnostic approach of hyperprolactinemia three pitfalls or potential confounding problems deserve special attention: pituitary incidentalomas, the hook effect and macroprolactinemia. In as much as 10% of the population aged 20 to 40 years, incidental tumors of the pituitary gland are demonstrated by magnetic resonance imaging. The hook effect is characterized by the finding of falsely low levels of serum prolactin (PRL) when two-site immuno-assays are used in diagnosis in patients with very high prolactin levels. This confusion can […]

In children, hypothyroidism is a rare cause of precocious puberty. We report the case of a child with incomplete precocious puberty (no activation of the hypothalamus-pituitary axis demonstrated by a negative LH-RH stimulation test), hyperprolactinemia and reduction of growth velocity as a consequence of primary hypothyroidism. Treatment of the thyroid disease led to regression of the pubertal development and resumption of growth.

Serum prolactin measurement is a routine test in several conditions in every day clinical practice, and the finding of hyperprolactinemia can induce complex and expensive imaging studies. Circulating prolactin is a heterogeneous hormone and, from a molecular weight point of view, there are three main forms: the 23kDa monomer, the 45kDa dimer (big prolactin) and the higher than 150kDa macroprolactin, or big-big prolactin. In normal conditions, or in patients with symptomatic hyperprolactinemia, the monomeric form is the predominant. Macroprolactin is […]