Can children have hyperprolactinemia?

Hyperprolactinemia in Children and Adolescents

Yes, children can have hyperprolactinemia, which is well-documented in pediatric populations with various etiologies similar to adults, though it is relatively rare before puberty. 1

Epidemiology

• Hyperprolactinemia is uncommon in prepubertal children but becomes more prevalent during adolescence, especially after age 12 1
• Prolactinomas, the most common pituitary adenoma type in children and young people (CYP), occur in approximately 0.1 million children annually 1
• Hyperprolactinemia shows a strong female predominance (3-4.5 times more common in females than males) 1, 2
• Most cases present during adolescence, with a median age of diagnosis around 15 years 2

Etiology

Hyperprolactinemia in children can result from various causes:

Pathological Causes

• Prolactinomas: Most common pathological cause of chronic hyperprolactinemia 3, 4

  • Exceptionally rare before puberty, when corticotropinomas are more common 1
  • 93% of pediatric prolactinomas present after 12 years of age 1
  • Can be microadenomas or macroadenomas (the latter more common in pediatric patients than adults) 1

• Other Pituitary/Hypothalamic Disorders 2:

  • Non-functioning pituitary adenomas
  • Craniopharyngiomas
  • Empty sella syndrome

Physiological/Secondary Causes

• Medications: One of the most common causes of hyperprolactinemia 1, 3

  • Antipsychotics (particularly risperidone in 82% of drug-induced cases) 2
  • Other dopamine antagonists 3

• Endocrine Disorders:

  • Primary hypothyroidism (reported in 43% of women and 40% of men with frank primary hypothyroidism) 1, 3
  • Polycystic ovary syndrome (PCOS) - found to be the most common cause in some recent studies 2

• Other Medical Conditions:

  • Chronic kidney disease (30-65% of adult patients) 1, 3
  • Severe liver disease 1, 3
  • Tetrahydrobiopterin deficiencies (rare neurometabolic disorders) 1

• Other Causes:

  • Macroprolactinemia (10-40% of hyperprolactinemia cases) 1
  • Idiopathic hyperprolactinemia 2
  • Stress-induced elevation 3, 5

Clinical Presentation

Symptoms vary by age, sex, and severity:

• Prepubertal Children:

  • Headache 1
  • Visual disturbances (with macroadenomas) 1
  • Growth failure or short stature 1
  • Delayed puberty 1, 6

• Adolescent Girls:

  • Menstrual irregularities (most common) 1, 7, 2
  • Primary or secondary amenorrhea 1, 6
  • Galactorrhea 1, 7, 2
  • Delayed puberty 6

• Adolescent Boys:

  • Headache (more common than in girls) 1
  • Gynecomastia 1, 7
  • Delayed puberty or pubertal arrest 1
  • Visual field defects (more common in boys) 1

• General Symptoms:

  • Weight gain/obesity (present in 48.8% of patients in recent studies) 2
  • Mass effect symptoms with macroadenomas (headache, visual changes) 1

Diagnostic Approach

• Laboratory Testing:

  • Measure serum prolactin in a single blood sample collected at any time of day 1, 5
  • Consider serial measurements for modestly elevated levels to exclude stress-related elevation 1, 5
  • Use age-specific and sex-specific reference ranges 1
  • Assess macroprolactin levels when prolactin is mildly or incidentally elevated 1
  • Perform serial dilutions of serum for prolactin measurement in patients with large pituitary lesions and normal or mildly elevated prolactin levels 1

• Exclude Confounding Conditions:

  • Hypothyroidism 1, 3, 5
  • Renal or hepatic impairment 1, 3, 5
  • Medication-induced hyperprolactinemia 1, 3, 5
  • Pregnancy (in adolescent girls) 1

• Imaging:

  • MRI of the pituitary when prolactin levels are significantly elevated 5

Treatment

• Prolactinomas:

  • Dopamine agonists are first-line treatment 4, 8
  • Cabergoline is highly effective and practical due to biweekly dosing 7, 2
  • Bromocriptine is an alternative, though safety is established in patients age 16 and older 9
  • Surgery is indicated for patients unresponsive or intolerant to medical treatment 8

• Drug-induced Hyperprolactinemia:

  • Discontinuation or switching of the causative medication when possible 2

• Other Causes:

  • Treat the underlying condition (e.g., hypothyroidism, renal disease) 3

Monitoring and Outcomes

• Prolactin levels typically normalize within 2-3 months of appropriate treatment 4
• Cabergoline treatment achieves approximately 50% reduction in adenoma size in the first year 4
• Long-term follow-up is required after discontinuing treatment due to risk of relapse 4
• Cabergoline has shown 100% success rate in pediatric prolactinoma patients in recent studies 2

Special Considerations

• The safety and effectiveness of bromocriptine for prolactin-secreting pituitary adenomas is established in patients 16 years and older 9
• Limited data exists for children under 8 years of age 9
• For children 11-15 years with prolactinomas, evidence shows variable response to bromocriptine (9 successful outcomes, 3 partial responses, and 2 failures out of 14 reported patients) 9
• Chronic hypopituitarism may complicate macroadenoma treatment 9