Commonly used tests for hyperprolactinemia

The clinical manifestations of hyperprolactinemia mainly include menstrual disorders, galactorrhea, infertility, headache, decreased vision and visual field defects. What are the commonly used examination methods for hyperprolactinemia? Because the examination of hyperprolactinemia is very professional, the following editor will introduce the examination methods of hyperprolactinemia to you.

1. Hypothalamus-pituitary-ovarian axis reproductive hormone measurement: FSH and LH decrease, LH/FSH ratio increases. If PRL ≤ 100 ng/ml, it is mostly functional increase, and PRL ≥ 100 ng/ml is mostly tumor increase. The larger the tumor, the higher the PRL. For example, if the tumor diameter is ≤ 5 mm, PRL is (171 ± 38) ng/ml; if the tumor diameter is 5-10 mm, PRL is (206 ± 29) ng/ml; if the tumor diameter is ≥ 10 mm, PRL is mostly (485 ± 158) ng/ml, which is a giant adenoma.

2. 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 glucose, and glucagon should be measured and a glucose tolerance test should be performed.

3. 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, thereby promoting PRL secretion. In normal women, after intramuscular injection of 25-50 mg of chlorpromazine, blood PRL increases by 1-2 times compared with before injection within 60-90 minutes and lasts for 3 hours. It does not increase in patients with 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 did not increase in patients with pituitary tumors.

4. 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 to 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, after taking 2.5-5 mg orally for 2-4 hours, PRL decreases by more than 50% and lasts for 20-30 hours. In patients with functional hyperprolactinemia and prolactinoma, prolactin is significantly reduced after taking the drug, while GH and ACTH are reduced, but the reduction of GH and ACTH is not obvious.

1. Sella CT scan: In normal women, the anterior-posterior diameter of the sella turcica is <17mm, the depth is <13mm, the area is <130mm2, and the volume is <1100mm3. CT scan should be performed if the following images are present:

①Expanded like a sailboat;

②Double saddle bottom or heavy edge;

③High/low density area or inhomogeneity within the saddle;

④ Deformation of the plate;

⑤ Suprasellar calcification;

⑥ Osteoporosis of the anterior and posterior clinoid processes;

⑦ Intrasellar cavitation;

⑧Bone 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: including 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.).

The above is an introduction to the commonly used examination methods for hyperprolactinemia. I hope it will be helpful to you.