How is hyperprolactinemia diagnosed?

Hyperprolactinemia is a very destructive disease and is a type of pituitary disease. Hyperprolactinemia is relatively common. Patients with hyperprolactinemia will have symptoms of galactorrhea and varying degrees of hypogonadism. Female patients with hyperprolactinemia will have symptoms of decreased libido and even loss of sexual desire, but it can be treated and will be relieved as the level of hyperprolactinemia decreases after treatment.

1. Can a single high blood prolactin test diagnose hyperprolactinemia?

If the prolactin level is between 25 and 40 ng/ml, the answer is no. Because a single blood test shows that the prolactin level is higher than normal, it is not enough to diagnose hyperprolactinemia. Because prolactin is secreted in a pulsed manner, and stress can increase the secretion of prolactin. Hyperprolactinemia can only be diagnosed after other causes of elevated prolactin are excluded by taking a medical history (especially medication history), a pregnancy test, and checking thyroid and kidney function.

2. What tests need to be done after hyperprolactinemia is diagnosed:

After excluding other causes of elevated prolactin, patients with hyperprolactinemia should undergo sellar enhanced MRI examination. Peking Union Medical College Hospital generally adopts sellar dynamic enhanced MRI, which can detect pituitary adenomas of 2 to 3 mm in size. According to the size of the tumor, pituitary adenomas are divided into microadenomas with a diameter of <1 cm and macroadenomas with a diameter of 1 to 3 cm. For patients whose tumors are higher than the pituitary fossa, visual field examinations and anterior pituitary function examinations are also required. Anterior pituitary function includes adrenal function (blood F, 24UFC, ACTH), thyroid function (thyroid function 1 to 3) and gonadal function (FSH, LH, E2 and T).

The blood prolactin level is proportional to the size of the tumor. The prolactin level of a macroadenoma is generally over 250ng/ml. In special cases, the tumor is very large, but prolactin is slightly elevated. There are two reasons for this. First, the tumor is not a prolactin adenoma, but a secondary increase in prolactin caused by the tumor compressing the pituitary stalk; second, it is a hook phenomenon. That is, the prolactin level in the blood is too high to be measured, and the blood sample needs to be diluted and re-measured.