What tests can be used to detect hyperprolactinemia?

What tests can be used to rule out hyperprolactinemia? The examination items for hyperprolactinemia include thyroid, adrenal and pancreatic function tests, hypothalamus-pituitary-ovarian axis reproductive hormone determination, prolactin inhibition test, prolactin stimulation test, etc. The following is a detailed introduction to you.

The main examination items for screening hyperprolactinemia are as follows:

1. Thyroid, adrenal and pancreatic function tests: When hyperprolactinemia is combined with hypothyroidism, TSH is elevated, and T3, T4, and PBI are decreased. When hyperprolactinemia is combined with Cushing's disease and virilization symptoms, testosterone (T), androstenedione (△4dione), dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA), 17-ketosteroids (17KS) and plasma cortisol are elevated. When hyperprolactinemia is combined with diabetes and acromegaly, plasma insulin, blood sugar, glucagon and a glucose tolerance test should be measured.

2. Hypothalamus-pituitary-ovarian axis reproductive hormone measurement: FSH and LH decreased, and the LH/FSH ratio increased. If PRL ≤ 100ng/ml, it is mostly functional increase, and PRL ≥ 100ng/ml is mostly tumor increase. The larger the tumor, the higher the PRL. For example, if the tumor diameter is ≤ 5mm, the PRL is (171±38)ng/ml; if the tumor diameter is 5~10mm, the PRL is (206±29)ng/ml; if the tumor diameter is ≥ 10mm, the PRL is mostly (485±158)ng/ml. Plasma PRL may not increase when giant adenoma bleeds and necrotizes.

3. Prolactin suppression test

(1) Levodopa test: Levodopa is a dopamine precursor that is converted into dopamine by decarboxylase, inhibiting the production and secretion of PRL. In normal women, PRL is significantly reduced 2-3 hours after oral administration of 500 mg, but it does not decrease in patients with pituitary tumors.

(2) Bromocriptine test: Levodopa is a dopamine receptor agonist that inhibits the production and release of PRL. In normal women, PRL decreases 2 to 4 hours after taking 2.5 to 5 mg orally, and lasts for 20 to 30 hours. In patients with functional hyperprolactinemia and prolactinoma, prolactin decreases significantly after taking the drug, while GH and ACTH decrease, but GH and ACTH decrease not significantly.

1. Sella turcica computed tomography (CT) examination shows that the anterior-posterior diameter of the sella turcica in normal women is <17mm, the depth is <13mm, the area is <130mm2, and the volume is <1100mm3. CT should be performed if the following images are present: ① sailboat-shaped enlargement; ② double sella turcica bottoms or double edges; ③ high/low density areas or inhomogeneity within the sella turcica; ④ plate deformation; ⑤ suprasellar calcifications; ⑥ anterior and posterior clinoid osteoporosis; ⑦ cavitation within the sella turcica; ⑧ bone destruction.

2. Magnetic resonance imaging (MRI), cavernous sinus angiography, pneumoencephalography, and cerebral angiography can determine the location and size of the tumor and help differentiate it from other intracranial lesions. Since the false positive and false negative rates of CT diagnosis are 20% and the accuracy rate is only 61%, MRI is recommended for diagnosis.

3. Ophthalmological examination includes visual acuity, visual field, intraocular pressure, and fundus examination to determine whether there are signs of intracranial tumor compression (bitemporal visual field hemianopsia, decreased vision, blindness, nausea, vomiting, and headache, etc.).

4. Prolactin stimulation test

(1) Thyrotropin-releasing hormone (TRH) test: In normal women, a single intravenous injection of TRH 100-400 pg is given. Within 15-30 minutes, PRL increases 5-10 times compared to before injection, and TSH increases 2 times. There is no increase in patients with pituitary tumors.

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

(3) Metoclopramide test: Metoclopramide promotes the production 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, but it did not increase in pituitary tumors.