Exxcellence pearls: Hyperprolactinemia

Question 0

What are examples of physiologic causes of hyperprolactinemia?

Answer 0

Stress, nipple stimulation, sleep, exercise, coitus, pregnancy and lactation

Question 1

Where is prolactin secreted from?

Answer 1

Lactotroph cells of the anterior pituitary gland.

Question 2

What broad categories are included in the differential diagnosis of hyperprolactinemia?

Answer 2

1. Physiologic causes
2. Pathologic causes
3. Pharmacologic causes
4. Idiopathic

Question 3

What are pharmacologic causes of hyperprolactinemia?

Answer 3

Antipsychotics, gastric motility drugs, antihypertensives, dopamine receptor blockers, opiates, and H2 antihistamines

Question 4

What are pathologic causes of hyperprolactinemia?

Answer 4

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

Question 5

What are the symptoms of hyperprolactinemia?

Answer 5

Oligomenorrhea, amenorrhea, infertility, galactorrhea, headaches and visual disturbances.

Question 6

What is the serum concentration that is considered abnormally elevated for prolactin?

Answer 6

20–25 ng/mL

Question 7

Laboratory testing should be ordered?

How is micro/macroadenoma diagnosed?

Answer 7

Prolactin and TSH

MRI

Question 8

What history should be emphasized for hyperprolactinemia?

Physical exam?

Answer 8

Medications, pregnancy, headache, visual symptoms, hypothyroidism symptoms, renal/liver disease

Signs of hypothyroidism, hypergonadism, visual field loss, Chest wall injury

Question 9

What is the threshold size that defines a microadenoma?

Answer 9

Less than 10 mm

Question 10

How are symptomatic patients with macroadenomas and hyperprolactinemia treated?

Answer 10

Bromocriptine or cabergoline

Question 11

What is the role of transsphenoidal surgery?

Answer 11

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)

Question 12

What is macroprolactinemia?

Answer 12

Large polymeric forms of prolactin and circulating anti-prolactin autoantibodies. These forms are less biologically active. 10-20% will have prolactinomas.

Question 13

What is known about dopamine agonist used during pregnancy?

Answer 13

Current data suggest bromocriptine is safe during the first month. Data for cabergoline is reassuring but insufficient.

Question 14

What is the main goal of treatment of women with lactotroth microadenomas?

Macroadenomas?

Answer 14

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.

Question 15

How is a lactotroph adenoma followed during pregnancy?

Answer 15

Women should be monitored for possible adenoma growth; growth that affects visual function should be treated with dopamine agonist or if necessary surgery in the second trimester.