Endocrine Abstracts

JOINT3216

Objective: This study aims to evaluate the etiological, clinical, and biochemical characteristics of pediatric patients diagnosed with hyperprolactinemia.

Methods: We analyzed 160 pediatric patients diagnosed with hyperprolactinemia between January 2018 and December 2024. Hyperprolactinemia was defined as prolactin levels exceeding 25 ng/mL in girls and 20 ng/mL in boys on at least two separate occasions, with blood samples taken between 8:00 AM and 9:00 AM. Patients were categorized into two groups based on the underlying etiology: Group-1: Pituitary and Hypothalamic Disorders (n = 38), including prolactinomas (n = 18), non-functioning pituitary adenomas (n = 8), craniopharyngiomas (n = 7), and empty sella (n = 5). Group-2: Non-Pituitary and Hypothalamic Disorders (n = 122), including polycystic ovary syndrome (PCOS) (n = 40), drug-induced hyperprolactinemia (n = 33), macroprolactinemia (n = 20), and idiopathic hyperprolactinemia (n = 29). Clinical presentations, biochemical findings, imaging results, and treatment responses were assessed.

Results: The median age at diagnosis was 15.2 years, (range: 2–17.9 years) with a female predominance of 73.1%. The median prolactin level was 45.8 ng/mL (range: 38.3–14,350). The median prolactin level in Group-1 was 213 ng/mL, which was significantly higher than the median level of 44 ng/mL observed in Group-2 (P < 0.05). However, there were no significant differences between the two groups in terms of age, weight, height, and BMI SDS. The most common presenting symptoms were menstrual irregularities, galactorrhea, headache, and pubertal delay. Overweight/obesity were evident in 47.5% of the overall study cohort. Patients with PCOS exhibited the highest prevalence of overweight/obesity, with a rate of 70%. Cabergoline treatment achieved a 100% success rate in patients with prolactinomas. Additionally, at the end of the first year of cabergoline treatment, a significant decrease in BMI SDS was observed in the patients with prolactinomas (P < 0.05), with a mean BMI SDS of 0.8 ± 1.6 at baseline and 0.3 ± 1.1 after one year of treatment. Risperidone was the responsible agent in 82% of patients with drug-induced hyperprolactinemia, and prolactin levels normalized after drug discontinuation or switching to an alternative medication.

Conclusion: Pediatric hyperprolactinemia exhibits a diverse etiological spectrum, with PCOS and drug-induced cases being more common than previously reported. Prolactin levels can help differentiate pituitary adenomas from other causes, guiding management. Given that mild prolactin elevations were frequently observed in PCOS, it may be considered part of the PCOS phenotype rather than a distinct pathology, potentially reducing unnecessary endocrinological or radiological evaluations. Cabergoline was highly effective in prolactinoma patients, also contributing to BMI reduction, while drug-induced hyperprolactinemia, primarily linked to risperidone, resolved with medication adjustment.