Chinese Experts Issue Updated Consensus on Diagnosing and Treating Prolactinomas

Prolactinomas, benign tumors of the pituitary gland that secrete the hormone prolactin, are the most common functional pituitary neuroendocrine tumors, accounting for roughly 46 to 66 percent of such tumors. Their population prevalence is estimated at about 37 per 100,000 people, with an annual incidence as high as 2.0 to 8.2 per 100,000. Now, the China Pituitary Adenoma Specialist Council has published a fully revised national consensus, updating a 2014 document with 36 formal recommendations covering screening, diagnosis, treatment, and long-term monitoring, along with individualized guidance for pregnant women, male patients, and refractory cases.

The updated consensus was initiated in October 2024 and developed by a working group of 60 experts spanning neurosurgery, endocrinology, obstetrics and gynecology, neuroradiology, radiation oncology, and evidence-based medicine methodology. The team followed the GRADE approach for rating evidence certainty, built evidence summaries using the Evidence-to-Decision framework, and searched six Chinese and international databases for literature published through April 30, 2025. Consensus was defined as agreement above 80 percent, and the guideline is registered under PREPARE-2025CN1518. The authors caution that because the overall quality of underlying evidence is limited, many recommendations carry low strength ratings and should be adapted to local clinical realities.

On diagnosis, the consensus recommends measuring serum prolactin in anyone with clinical suspicion: women of reproductive age with menstrual irregularities, infertility, or galactorrhea; men with reduced libido, erectile dysfunction, infertility, or gynecomastia; adolescents with delayed or arrested puberty or growth retardation; and patients whose imaging reveals a sellar region lesion. Among women of reproductive age with hyperprolactinemia, 85 to 90 percent present with oligomenorrhea or amenorrhea and 69 to 84 percent with galactorrhea. Among women with oligomenorrhea or secondary amenorrhea, 7.23 to 17.34 percent have hyperprolactinemia. Because prolactin is secreted in a pulsatile pattern, rising during sleep and reaching its nadir between 10:00 and 12:00 a.m., blood sampling is best performed in a resting state after an overnight fast and at least two hours of wakefulness.

The document also addresses two well-known diagnostic pitfalls. Macroprolactin, an inactive complex of prolactin monomers bound to immunoglobulin G, is detected by standard assays yet lacks biological activity; it is found in 5.32 to 22.90 percent of hyperprolactinemic patients, so screening with polyethylene glycol precipitation is advised when clinical findings and hormone levels disagree. At the other extreme, the Hook effect can cause falsely low prolactin readings when extremely high concentrations saturate assay antibodies. A 2025 systematic review of 61 macroprolactinoma patients with documented Hook effect found a mean prolactin concentration of 108.1 ng/ml before dilution but 38,526.9 ng/ml after dilution, underscoring the value of dilution testing in patients with large tumors and discordant biochemistry.

For imaging, pituitary magnetic resonance imaging remains the preferred modality, and dynamic contrast-enhanced MRI is specifically endorsed to improve detection of microadenomas smaller than one centimeter, which enhance more slowly than the normal dual-blood-supply pituitary gland. The consensus also weighs the risk of gadolinium retention, recommending that follow-up imaging frequency be tailored to symptoms and prolactin monitoring, with macrocyclic chelating agents preferred over linear ones. Macroadenomas can be re-imaged 3 to 6 months after starting dopamine agonist therapy, while responsive microadenomas may be imaged annually or less often. Notably, the guideline suggests preoperative CT or MR angiography for patients with invasive tumors, tumors contacting the internal carotid artery, or age over 50, since associated aneurysms occur in 2.3 to 8.3 percent of pituitary tumor patients, and aneurysm rupture during endoscopic resection can be fatal.

Treatment recommendations center on dopamine agonists, which are rated strongly with moderate-certainty evidence for lowering prolactin, shrinking tumors, and restoring gonadal axis function. Retrospective studies show bromocriptine normalizes prolactin in 68 percent of patients, while a literature review of 1,362 patients found cabergoline achieved biochemical remission in 79.7 percent overall, with 84.0 percent in microadenomas and 76.9 percent in macroadenomas. Because cabergoline is not yet available in mainland China, bromocriptine remains the first-choice agent there, started at low doses of 0.625 to 1.25 mg per day and titrated upward. The guideline highlights a frequently under-recognized harm: dopamine agonists can trigger impulse control disorders such as pathological gambling, compulsive shopping, and hypersexuality, with reported incidence in prolactinoma patients ranging from 9.8 to 52 percent. Young male patients and those with psychiatric histories warrant particular monitoring.

Surgery emerges as a genuine first-line contender for well-circumscribed tumors. In experienced centers, immediate postoperative biochemical remission reaches 90 to 100 percent for well-circumscribed microadenomas and 66.7 to 81.0 percent for macroadenomas with Knosp grades 0 to 1, with perioperative complications under 2 percent. A meta-analysis of 3,564 medically treated and 1,836 surgically treated patients found long-term remission of roughly 83 percent after surgery in microadenomas versus only 36 percent after withdrawing medical therapy. Prognosis depends heavily on tumor characteristics: preoperative prolactin levels of 200 ng/ml or below predict remission rates up to 92 percent, falling to about 40 percent above that threshold, and patients whose prolactin drops to 10 ng/ml or less on the first postoperative day showed no recurrence over five years of follow-up. For invasive tumors of Knosp grade 2 or higher, however, dopamine agonists remain the first choice; in a meta-analysis of 196 giant prolactinomas, drug therapy produced tumor shrinkage in 88 percent and visual improvement in 85 percent.

The consensus gives detailed attention to pregnancy, an area of longstanding clinical anxiety. Women with microprolactinomas need not stop medication when attempting conception, and once pregnancy is confirmed, discontinuation is recommended, since the risk of symptomatic tumor enlargement is only 1 to 5 percent. For macroadenomas, treatment beforehand reduces the risk of enlargement during pregnancy from 18 to 4.7 percent, and women are advised to shrink tumors to microadenoma size before conceiving. Evidence cited includes fetal malformation rates of 3.9 percent with first-trimester bromocriptine exposure and 2.7 percent with cabergoline, neither statistically different from baseline population risks. If tumor growth is suspected during pregnancy with new headaches or visual loss, non-contrast MRI is the preferred imaging test, dopamine agonists should be restarted, and surgery is reserved for the roughly 20 to 30 percent unresponsive to medication or facing acute visual loss, ideally in the second trimester.

The guideline closes with provisions for the hardest cases. Refractory pituitary tumors, defined by radiologically confirmed invasion, resistance to standard therapies, and high proliferative markers such as a Ki-67 index of 3 percent or more, and metastatic disease call for multidisciplinary management, with the chemotherapy agent temozolomide recommended as first-line when surgery, drugs, and radiotherapy fail. In a retrospective review of 94 patients with aggressive or metastatic prolactinomas, 62 percent achieved disease control or stabilization with temozolomide, and low MGMT expression predicted better response rates of 76 versus 14 percent. For radiotherapy, local tumor control ranges from 68 to 100 percent and biochemical remission from 30 to 80 percent, though normalization of prolactin may take 2 to 3 years and pituitary hormone deficiency remains the principal late complication. Breastfeeding is encouraged postpartum, with tumor enlargement during 12 months of lactation occurring in just 1.2 percent of microadenoma and 4.3 percent of macadenoma patients. The authors emphasize that the consensus carries no legal force and will be updated as medical evidence evolves.

Subject of Research: Updated Chinese clinical consensus recommendations for the diagnosis and treatment of prolactinomas

Article Title: Chinese consensus on the diagnosis and treatment of prolactinomas (2025 edition)

Article References: Lin, S., Chen, Z., Ji, L., Wang, L., Zhang, W., Tang, X., Wu, Y., Fan, Q., Li, J., Pan, L., Yao, Z., Deng, C., Ye, H., Li, S., Zhu, H., Zhao, Y., Wang, Y., Wu, Z. B., & China Pituitary Adenoma Specialist Council (2026). Chinese consensus on the diagnosis and treatment of prolactinomas (2025 edition). Chinese Neurosurgical Journal, 12(1), Article 17. https://doi.org/10.1186/s41016-026-00437-7

Image Credits: AI Generated

DOI: 10.1186/s41016-026-00437-7

Keywords: prolactinoma, pituitary adenoma, hyperprolactinemia, dopamine agonists, clinical consensus, pituitary MRI, pregnancy, transsphenoidal surgery, cabergoline, bromocriptine, temozolomide, GRADE methodology