Male Lactation (Galactorrhea) in AMAB Individuals: Diagnostic and Treatment Protocol
For AMAB individuals presenting with galactorrhea, immediately obtain serum prolactin, TSH, and renal function tests, followed by brain MRI if hyperprolactinemia is confirmed without medication cause, and treat with cabergoline as first-line therapy for prolactinomas or medication-induced hyperprolactinemia. 1, 2
Initial Diagnostic Workup
Immediate Laboratory Assessment
- Serum prolactin level is the single most critical test and should be obtained first 1, 2, 3
- Thyroid-stimulating hormone (TSH) to rule out hypothyroidism as a cause 1, 2
- Renal function tests (BUN/creatinine) since chronic renal failure causes hyperprolactinemia 1, 2
- Testosterone level may be indicated as hyperprolactinemia suppresses gonadotropins and testosterone production 2, 3
Medication Review
- Discontinue or replace causative medications if possible, as medication-induced hyperprolactinemia is the most common cause after infancy 1, 3
- Common culprits include antipsychotics, metoclopramide, SSRIs, and antihypertensives 2, 3
Imaging Protocol
When to Order Brain MRI
- Obtain MRI of the pituitary gland if hyperprolactinemia is confirmed and no medication cause is identified 1, 2
- MRI is essential to detect prolactinomas (most common pathologic cause) or other sellar/suprasellar lesions 1, 2, 3
- For males specifically, imaging is particularly important as the ACR Appropriateness Criteria note that male nipple discharge has a 23-57% cancer incidence, though this refers to bloody discharge rather than galactorrhea 4
Treatment Algorithm
For Hyperprolactinemia with Prolactinoma
- Cabergoline is the preferred first-line dopamine agonist due to superior efficacy and tolerability compared to bromocriptine 1, 3
- Bromocriptine is an alternative but less well-tolerated option 2, 3
- Transsphenoidal surgery is reserved for patients who fail high-dose cabergoline therapy or cannot tolerate dopamine agonists 1
- Radiation therapy is rarely required 3
For Medication-Induced Hyperprolactinemia
- Switch to an alternative medication from the same class with lower prolactin-elevating potential 2
- If discontinuation is not possible, treat with low-dose dopamine agonist 2
For Normoprolactinemic Galactorrhea
- Reassurance alone is appropriate if galactorrhea is not bothersome to the patient 2, 3
- Short course of low-dose dopamine agonist for bothersome symptoms in normoprolactinemic patients 2
Critical Considerations for AMAB Patients
Fertility Implications
- Hyperprolactinemia suppresses LH and FSH, leading to hypogonadism and potential infertility 2, 3
- Do NOT prescribe testosterone replacement therapy for hyperprolactinemia-induced hypogonadism in males desiring fertility, as exogenous testosterone further suppresses spermatogenesis 4
- Treatment of the underlying hyperprolactinemia with dopamine agonists will restore testosterone production naturally 2
Associated Symptoms to Assess
- Erectile dysfunction and decreased libido (from hypogonadism) 2, 3
- Visual field defects (if macroadenoma present) 3
- Headaches (from mass effect) 3
- Osteopenia/osteoporosis risk from prolonged hypogonadism 3
Common Pitfalls to Avoid
- Do not dismiss galactorrhea in males as purely physiologic—it requires full evaluation 1, 2
- Do not order MRI before checking prolactin and TSH—this wastes resources if a simple cause is identified 1, 2
- Do not treat with testosterone for associated hypogonadism without addressing the underlying hyperprolactinemia first 4
- Do not assume all nipple discharge is galactorrhea—bloody or unilateral discharge requires evaluation for malignancy per ACR guidelines 4