Endocrine Abstracts

Background: Systematic exploration for anterior pituitary deficiency in patients harboring pituitary microadenomas is not well defined. So far, little is known on the involvement of pituitary function in clinically non-functioning pituitary microadenomas (CNFPM).

Objective: To evaluate the prevalence of anterior pituitary insufficiency, defined as at least one hormonal deficiency, in patients diagnosed of CNFPM.

Patients and methods: A multicenter retrospective study in patients diagnosed of CNFPM was performed. In every patient, clinical parameters (age at a diagnosis, sex, and main complaint at presentation) and endocrine dysfunction (the presence of hypopituitarism, number of axes involved, and hyperprolactinemia) were recorded.

Results: Of a total of 162 patients with CNFP adenomas, 31 patients (19.1%; mean age 43.6±15.65 yr (range, 14–83); 21 women (67.7%)) with microadenomas (median size 5 mm (IQR, 4–7 mm) were evaluated. In most patients (n=23, 74.2%), the finding of the pituitary microadenoma was incidental. In the remaining, the main complain at presentation was galactorrhea (n=3), erectile dysfunction (n=2), infertility (n=1), amenorrhea (n=1) and menstrual disorders (n=1). Anterior pituitary insufficiency was seen only in 2 patients (6.5%), both of them with only one hormonal deficiency. The first one was a 51-year-old woman who complained of facial pain. Pituitary MRI showed a 5 mm pituitary microadenoma and hormonal evaluation was compatible with ACTH deficiency (low/normal ACTH (13 pg/ml) with low cortisol (3.8 μg/dl)). The second one was a 28-year-old man studied for infertility. Investigations showed hypogonadotropic hypogonadism (low FSH (0.2 mU/ml), low LH (0.4 mU/ml) and low total testosterone (20 ng/dl)). Pituitary MRI showed a 4 mm pituitary adenoma. In both patients serum PRL concentrations were into the normal range.

Conclusion: In our series, the percentage of pituitary hormone deficiencies associated with CNFPM was very low (6.5%). Although the relationship between CNFPM and pituitary hormone deficiency might be coincidental, it would seem appropriate and prudent to rule out pituitary hormonal insufficiency in these patients.