Intraductal papilloma of the breast !

A small non-cancerous growth inside a milk duct near the nipple. It is the most common cause of bloody discharge from one nipple.

Updated 2026-11-01

Structures involved

Tap one to see what it is and open it in 3D.

Why it happens

What it is

A benign papillary tumour growing inside a breast duct, made of fibrovascular cores covered by epithelial and myoepithelial cells; a solitary central papilloma is the most common cause of bloody nipple discharge.

Who gets it

Occurs most often in women aged about 35 to 55. Solitary central papillomas near the nipple are most common; multiple peripheral papillomas are less common and carry a higher risk of associated atypia or cancer.

Causes

Benign proliferation of ductal epithelium on a fibrovascular stalk
Cause unknown; hormonal influences suspected

Risk factors

Age 35 to 55
Multiple peripheral papillomas (higher associated cancer risk)
Coexisting atypical hyperplasia

Pathophysiology

The papilloma grows as a finger-like projection inside a large lactiferous duct, usually within a few centimetres of the nipple. Its fragile fibrovascular core twists or infarcts easily, producing serous or bloody discharge from a single duct opening. The preserved myoepithelial layer distinguishes it from papillary carcinoma. Peripheral papillomas in smaller ducts are more often multiple and associated with atypical hyperplasia or ductal carcinoma in situ.

Classification

Solitary central papilloma (large ducts near the nipple)
Multiple peripheral papillomas (terminal duct lobular units)
Papilloma with atypia or ductal carcinoma in situ

Symptoms and signs

Spontaneous bloody or serous discharge from one duct of one nipple
Small lump beneath or near the areola (sometimes)
Usually painless
Often found only on imaging

Diagnosis

Clinical: Spontaneous unilateral single-duct discharge, often bloody; pressure around the areola identifies the duct involved. Bilateral, multiduct milky discharge suggests a physiological or hormonal cause instead.
Tests: Core needle biopsy of any lesion seen on imaging; cytology of discharge is of limited value. Pregnancy test and prolactin if discharge is milky.
Imaging: Targeted ultrasound of the retroareolar area and mammography (age-appropriate); ductography or breast MRI when ultrasound and mammography are negative.

Differential diagnosis

Ductal carcinoma in situ or papillary carcinoma
Mammary duct ectasia
Fibrocystic breast changes
Galactorrhoea from hyperprolactinaemia
Periductal mastitis

Goal of treatment

Exclude cancer, stop troublesome discharge, and remove lesions with atypia or uncertain features.

Treatment

Surgical: Excision of the affected duct (microdochectomy) or of the papilloma, especially with persistent bloody discharge, atypia on biopsy, or discordance between imaging and pathology.
Procedure: Vacuum-assisted excision under imaging guidance for selected small papillomas without atypia.
Follow-up: Imaging follow-up for small papillomas without atypia confirmed on core biopsy, and closer surveillance when multiple papillomas or atypia are present.

Complications

Persistent or recurrent nipple discharge
Coexisting atypia or ductal carcinoma in situ found at excision
Slightly increased later breast cancer risk with multiple papillomas or atypia
Recurrence

Prognosis

Excellent; a solitary papilloma without atypia does not significantly raise breast cancer risk. Multiple papillomas and those with atypia raise risk modestly and need surveillance.

Test yourself

Think of the answer, then tap the question to see it.

What is the most common cause of spontaneous bloody discharge from a single nipple duct in a 45-year-old woman?

Intraductal papilloma.

Which cell layer distinguishes a benign papilloma from papillary carcinoma?

The preserved myoepithelial layer.

What is the first-line imaging for unilateral bloody nipple discharge in a woman over 40?

Mammography plus targeted retroareolar ultrasound.

Which surgical procedure removes the affected single duct?

Microdochectomy (single-duct excision).

Add to my cards (4)

Educational information, not medical advice. For any symptom, see a health professional.

Sources: Intraductal Papillomas of the Breast (American Cancer Society, 2024).

← All conditions

Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake

Representative model, for educational purposes only.