Intraductal papilloma (IDP) is a benign intraductal proliferative lesion arising from the epithelium of the mammary duct system. It occurs most frequently in women aged 30–50 years and may be solitary (central) or multiple (peripheral). Symptom expression correlates with lesion location, size, and the presence of epithelial atypia.

1. Spontaneous nipple discharge
   Unilateral, single-duct discharge is the hallmark symptom. Discharge is typically serous, serosanguinous, or frankly bloody; blood-stained fluid reflects torsion or ischaemia of the papillary stalk .
2. Palpable subareolar mass
   A small, firm, mobile nodule may be felt behind the nipple; tenderness is uncommon unless secondary infection or haemorrhage has occurred .
3. Localised breast pain or discomfort
   A dull, pulling sensation beneath the areola can accompany ductal distension; pain is usually mild and non-cyclical.
4. Peri-menstrual fluctuation
   Central papillomas may enlarge or become more tender during the luteal phase due to oestrogen stimulation; size often regresses after menstruation.
5. Multiple or peripheral lesions
   Peripheral papillomatosis presents as clustered, ill-defined masses rather than discharge; this form carries a higher risk of associated atypia or malignancy .
6. Incidental imaging detection
   Small, non-palpable papillomas are increasingly discovered on screening ultrasound or mammography; they appear as well-circumscribed intraductal nodules with gentle posterior enhancement .
7. Warning signs requiring excision
   Persistent bloody discharge, rapid growth, irregular margins, or concurrent atypical ductal hyperplasia on biopsy mandate complete surgical excision to exclude co-existing carcinoma .