Epidemiology & Risk Factors
Physiologic / Galactorrhea :
Medications : Antipsychotics (dopamine D2 antagonists), TCAs, SSRIs, metoclopramide, verapamil, OCPs.Endocrine : Pituitary adenoma (prolactinoma), primary hypothyroidism (↑ TRH stimulates PRL secretion), CKD (↓ PRL clearance), cirrhosis.Physiologic stimulation : Pregnancy, lactation, chest wall trauma/burns, sexual stimulation, vigorous exercise/tight bras.
Pathologic :
Intraductal papilloma : Most common cause of pathologic/bloody discharge (benign tumor of lactiferous duct).Malignancy (DCIS, Invasive Ductal Carcinoma, Paget disease) : Advanced age (≥ 50 yo), nulliparity, early menarche/late menopause, BRCA1/2 mutations, family history.Mammary duct ectasia : Perimenopausal/postmenopausal women, smoking history.
Clinical Features
Physiologic : Bilateral , multiductal, non-bloody (milky/green/yellow) , expressed on manipulation, no breast masses. c Pathologic : Unilateral , single-duct, spontaneous , bloody (sanguineous) or serosanguineous, ± palpable mass or skin changes.
Diagnosis
Initial Step (All) : Urine/serum β-hCG + bilateral CBE.Physiologic / Galactorrhea Workup :
Labs : Serum PRL , TSH , BUN/Cr.Imaging : Pituitary MRI (if PRL elevated and TSH/meds normal).
Pathologic Workup (Age-based) :
Age < 30 : Targeted Breast US (add MMG if suspicious).Age ≥ 30 : Diagnostic MMG + Targeted US .
Gold Standard / Confirmatory :
Core Needle Biopsy (CNB) : If imaging reveals a mass (BI-RADS 4/5).Subareolar Duct Excision : Diagnostic & therapeutic gold standard if imaging is negative or shows intraductal papilloma.
Differential Diagnostics
Intraductal Papilloma : Unilateral, spontaneous, bloody discharge ; no palpable mass or skin retraction.Invasive Carcinoma / DCIS : Unilateral bloody discharge + fixed hard mass, microcalcifications or spiculated mass on MMG.Paget Disease : Eczematous/ulcerated nipple-areolar complex with bloody discharge; underlying malignancy in > 80%.Mammary Duct Ectasia : Multicolored, sticky, thick green/brown discharge in perimenopausal women; subareolar duct dilation.Prolactinoma : Bilateral galactorrhea + amenorrhea/oligomenorrhea , PRL > 100 ng/mL.
Management
Physiologic / Drug-Induced : Reassurance, avoid stimulation; discontinue/switch offending drug.Prolactinoma :
1st-line: Dopamine agonists (Cabergoline > Bromocriptine) .
Refractory / Visual defects: Transsphenoidal resection.
Intraductal Papilloma : Subareolar duct excision (microdochectomy) .Malignancy : Breast-conserving surgery + RT vs. Mastectomy + SLNB ± adjuvant chemo/endocrine therapy.
Complications
Delayed diagnosis of invasive breast cancer.
Pituitary macroadenoma: Bitemporal hemianopsia (optic chiasm compression), pituitary apoplexy.
Post-excision: Loss of nipple sensation, inability to breastfeed from affected breast.