How high is prolactin? Is it a pituitary tumor?

The normal level of prolactin is less than 20µg/L, and it can reach more than 3 times during the menstrual period. If the prolactin level is seriously exceeded, it will cause hyperprolactinemia, and exceeding 300 may be a symptom of a pituitary tumor. Therefore, if women are found to have high prolactin levels, they should take medication in time, and if a pituitary tumor is found, the tumor should be removed immediately. They also need to understand how to prevent elevated prolactin.

Normal prolactin levels are generally ≤20µg/L. When the physiological amplitude is within 3 times, dynamic observation is recommended clinically. When the prolactin level exceeds 200µg/L, hyperprolactinemia should be considered. If it exceeds 300µg/L, hyperprolactinemia and pituitary hyperprolactinoma can basically be diagnosed. We need to remind everyone that prolactin testing cannot be done at any time and anywhere.

First of all, when measuring prolactin, pulsatile secretion and high-protein diet can affect the prolactin measurement, so prolactin measurement needs to be performed on an empty stomach every day. Daily fasting generally refers to 9-11 o'clock in the morning. You need to be in a resting state for 1 hour and eliminate pulse blockage before measuring, otherwise it will affect the prolactin test results. Secondly, rule out the effects of drugs on prolactin. Generally speaking, drugs such as contraceptives will affect the measurement of prolactin, so it is necessary to stop taking the drugs for 48-72 hours before going to the hospital for another check-up.

In clinical work, if prolactin is found to be elevated, and it is within about 3 times, it can be observed. There is no need to be particularly anxious or to take special measures, and other causes of hyperprolactinemia must be ruled out.

Clinical manifestations of prolactinoma

The clinical symptoms of high PRL blood caused by prolactinoma vary depending on gender, age, duration of high PRL blood and tumor size. It is more common in women and often manifests as galactorrhea-amenorrhea syndrome. Tumor size was positively correlated with serum PRL concentration in patients.

1. PRL tumor in women

It occurs in young women aged 20 to 30 and is often a microadenoma. The typical clinical manifestations are the triad of amenorrhea, galactorrhea and infertility. The main symptoms in pre-pubertal women are delayed puberty, growth retardation and primary amenorrhea, and in post-pubertal women are shortened menstrual period, scanty or excessive menstrual flow, delayed menstruation, decreased or absent libido, loss of sexual desire, lack of orgasm, pain during intercourse, miscarriage, infertility, etc. Physical signs may include breast atrophy, pubic hair loss, vulvar atrophy, and decreased vaginal secretions.

2. Male PRL tumor

Prolactinomas in men are larger, tend to develop above the sella turcica, and are relatively rare. The main clinical manifestations are complete or partial sexual dysfunction, such as loss of libido, impotence, male breast development, male infertility, decreased sperm count, etc. Symptoms progress slowly and are not easily taken seriously. By the time of diagnosis, the disease is already in the late stage. Imaging examinations often show large adenomas with obvious nerve compression. Physical examinations reveal that adolescent patients may have stagnation of puberty, abnormal body shape, breast development and lactation, and small testicles, while adults may have sparse beards, breast development and lactation, sparse pubic hair, and soft testicles.

3. Tumor compression syndrome

Advanced PRL tumors and other types of pituitary adenomas, hypothalamic and parasellar tumors extend above the sella due to their huge tumor size, blocking PIF and causing hyperPRLemia. Common local compression symptoms are headache and visual abnormalities. The cause of the headache is increased intracranial pressure caused by the macroadenoma, accompanied by nausea and vomiting. The incidence of headache in male patients with PRL tumors is higher than that in female patients. Some microadenomas have small space-occupying lesions and may also cause headaches. The reason is still unclear.

4. Osteoporosis

Patients with PRL tumors and long-term high PRL blood levels sometimes present with osteoporosis as their first symptom. After treatment restores normal prolactin levels and gonadal function, bone density can improve but sometimes does not return to normal.

5. Acute pituitary stroke

If a fast-growing PRL tumor has intratumoral bleeding, acute pituitary stroke may occur, which is manifested by sudden severe headache, nausea, vomiting, decreased vision and other symptoms of cranial nerve compression, and even coma and exophthalmos, requiring emergency treatment. Patients may develop hypopituitarism after successful rescue.