Exxcellence pearls: Hyperprolactinemia Flashcards
What are examples of physiologic causes of hyperprolactinemia?
Stress, nipple stimulation, sleep, exercise, coitus, pregnancy and lactation
Where is prolactin secreted from?
Lactotroph cells of the anterior pituitary gland.
What broad categories are included in the differential diagnosis of hyperprolactinemia?
- Physiologic causes
- Pathologic causes
- Pharmacologic causes
- Idiopathic
What are pharmacologic causes of hyperprolactinemia?
Antipsychotics, gastric motility drugs, antihypertensives, dopamine receptor blockers, opiates, and H2 antihistamines
What are pathologic causes of hyperprolactinemia?
Hypothalamic-pituitary stock damage due to trauma, radiation, Rathke’s cyst, infiltrative diseases and parasellar tumors
Pituitary disorders such as prolactinomas, acromegaly, and macroprolactinemia
Systemic disorders such as primary hypothyroidism, Chest wall injury due to trauma, surgery, herpes zoster, chronic renal failure with decreased clearance of prolactin, cirrhosis, malignancies such as renal or lung cancer
What are the symptoms of hyperprolactinemia?
Oligomenorrhea, amenorrhea, infertility, galactorrhea, headaches and visual disturbances.
What is the serum concentration that is considered abnormally elevated for prolactin?
20–25 ng/mL
Laboratory testing should be ordered?
How is micro/macroadenoma diagnosed?
Prolactin and TSH
MRI
What history should be emphasized for hyperprolactinemia?
Physical exam?
Medications, pregnancy, headache, visual symptoms, hypothyroidism symptoms, renal/liver disease
Signs of hypothyroidism, hypergonadism, visual field loss, Chest wall injury
What is the threshold size that defines a microadenoma?
Less than 10 mm
How are symptomatic patients with macroadenomas and hyperprolactinemia treated?
Bromocriptine or cabergoline
What is the role of transsphenoidal surgery?
Dopamine agonist treatment is unsuccessful or a woman with a greater than 3 cm adenoma wishes to become pregnant (the adenoma would likely grow before delivery when the dopamine agonist is discontinued)
What is macroprolactinemia?
Large polymeric forms of prolactin and circulating anti-prolactin autoantibodies. These forms are less biologically active. 10-20% will have prolactinomas.
What is known about dopamine agonist used during pregnancy?
Current data suggest bromocriptine is safe during the first month. Data for cabergoline is reassuring but insufficient.
What is the main goal of treatment of women with lactotroth microadenomas?
Macroadenomas?
Use dopamine agonist to lower serum prolactin into the normal range to induce ovulation.
Use dopamine agonists or perform transsphenoidal surgery to decrease tumor size before attempting to conceive.