Routine diagnostic sequence for hyperprolactinemia

The following are some of the diagnoses that should be considered for patients with hyperprolactinemia: physical examination, endocrine function tests, and prolactin function tests. So, what is the routine diagnostic sequence for hyperprolactinemia?

Routine diagnostic sequence for hyperprolactinemia:

1. Physical examination

Physical examination. Pay attention to the presence of acromegaly, myxedema and other symptoms. Gynecological examination to understand whether the genitals and sexual characteristics are atrophic and have organic lesions. Breast examination to pay attention to size, shape, presence of lumps, inflammatory milk discharge (gently squeeze the breasts with both hands). The characteristics and amount of discharge.

2. Endocrine function test

(I) Pituitary function: FSH and LH decrease, and the LH/FSH ratio increases. PRL increases ≥25ng/ml. It is generally believed that <100ng/ml is mostly functional. ≥100mg/ml should be careful to exclude PRL adenoma. The larger the tumor, the higher the PRL. If the tumor diameter d≤5mm, PRL is 171±38ng/ml; d=5～10mm206±29ng/ml; ≥10mm485±158ng/ml. PRL may not increase when giant adenoma hemorrhages and necrotizes.

It should be pointed out that the PRL radiotherapy kit currently used in clinical practice can only measure small molecule PRL (MW 25000), but cannot measure large/large molecule (MW 5-100000) PRL. Therefore, for some patients with obvious clinical symptoms but normal PRL, the so-called occult hyperprolactinemia (occult hyperprolactinemia), that is, large/large molecule hyperprolactinemia, cannot be ruled out.

3. Prolactin function test

(I) Prolactin stimulation test

1. Thyrotropin-releasing hormone test (TRH test): Normal women receive a single intravenous injection of TRH 100-400 μg. Within 15-30 minutes, PRL increases 5-10 times and TSH increases 2 times compared to before injection. It does not increase in cases of pituitary tumors.

2. Chlorpromazine test: Chlorpromazine inhibits the absorption of norepinephrine and the conversion of dopamine through receptor mechanism, and promotes PRL secretion. In normal women, blood PRL increases 1 to 2 times compared with before injection 60 to 90 minutes after intramuscular injection of 25 to 50 mg, and lasts for 3 hours. It does not increase in pituitary tumors.

3. Metoclopramide test: This drug is a dopamine receptor antagonist that promotes the synthesis and release of PRL. In normal women, 30 to 60 minutes after intravenous injection of 10 mg, PRL increased by more than 3 times compared with before injection. It does not increase in pituitary tumors.

(II) Prolactin suppression test

1. L-Dopa test: This drug is a dopamine precursor, which generates DA through the action of dehydroxylase and inhibits PRL secretion. In normal women, PRL is significantly reduced 2 to 3 hours after oral administration of 500 mg. It does not decrease in pituitary tumors.

2. Bromocriptine test: This drug is a dopamine receptor agonist that strongly inhibits PRL synthesis and release. Normal women take 2.5-5.0 mm orally and PRL decreases by ≥50% in 2-4 hours, which lasts for 20-30 hours. Functional HPRL and PRL decrease significantly in adenomas, while GH and ACTH decrease less than the former two.

We are all very clear about the routine diagnostic sequence of hyperprolactinemia. When hyperprolactinemia is discovered in life, we must choose the right treatment method. We must strive for early treatment. Only in this way can we have a healthy body. I wish the patients a speedy recovery!