Nipple retraction

Nipple retraction is inward pulling of the nipple, with the tip drawn behind the plane of the areola. It is either long standing and congenital (inversion), or a new acquired change that may signal an underlying breast cancer or inflammatory disease. Recent onset in an adult needs triple assessment.

Clinical relevance. Congenital inversion affects about 2 to 10% of women and is benign. Acquired retraction is uncommon, and is caused by traction from a retroareolar or periductal lesion, so duration and symmetry are the main discriminators.

Anatomy and mechanisms. Fibrous contraction of shortened lactiferous ducts, periductal inflammation and fibrosis, or tumour traction draws the nipple inward. Congenital inversion results from short ducts and weak connective tissue tethering the nipple.

Classification.

• Congenital or developmental inversion (Han and Hong grades): grade 1, easily everted and holds its shape; grade 2, can be everted but retracts again; grade 3, cannot be everted.
• Acquired retraction: new, usually unilateral, in a woman over 30 years.
• Slit like retraction (transverse, symmetrical) is more often benign (duct ectasia), while eccentric, fixed or distorted retraction suggests malignancy.

Key distinctions. Bilateral long standing inversion since puberty is benign. New unilateral retraction, with a mass, discharge, skin change or fixity, is cancer until proved otherwise.

History.

• Age at onset, duration, progression, symmetry, whether the nipple can be everted, and whether retraction changes with arousal, cold or lactation.
• Associated lump, pain, discharge (colour, spontaneity), skin change, fever, breast size change and axillary swelling.
• Previous breast or nipple surgery, trauma, radiotherapy, breastfeeding history and nipple piercing.
• Recurrent periareolar infection or abscess, smoking (periductal mastitis), diabetes and immunosuppression.
• Weight loss, night sweats, cough and tuberculosis contact in endemic settings.
• Breast cancer risk factors and family history.

Examination.

• Inspect both nipples with the patient seated and arms raised, then pressing the hands on the hips: note symmetry, the direction of retraction, a transverse slit, skin tethering and areolar distortion.
• Test eversion by gentle traction or squeezing behind the areola. Note nipple surface eczema, crusting, ulceration and discharge.
• Palpate both breasts, retroareolar tissue and axillae for mass, thickening and nodes.
• Skin changes: peau d'orange, dimpling, erythema.
• General examination for features of tuberculosis and other systemic illness when relevant.

Red flags.

• New retraction in an adult, especially unilateral and eccentric or fixed.
• Associated palpable mass, skin dimpling, peau d'orange or thickening.
• Bloody nipple discharge or nipple eczema, ulceration or crusting.
• Axillary or supraclavicular nodes.
• Painful red swollen breast with fever (abscess or inflammatory cancer).
• Rapid change over weeks.

Special groups. Pregnancy and lactation: inversion may cause feeding difficulty, and acquired change still needs triple assessment. Men: new retraction with a mass needs triple assessment. Older women: duct ectasia and cancer predominate.

Congenital and developmental. Nipple inversion (grades 1 to 3), shortened lactiferous ducts, asymmetry of puberty.

Inflammatory and benign acquired.

• Duct ectasia and periductal mastitis (associated with smoking).
• Subareolar abscess and mammary duct fistula.
• Fat necrosis after trauma or surgery.
• Granulomatous mastitis, tuberculous mastitis (endemic regions), sarcoidosis.
• Radial scar and sclerosing lesions, and scarring after surgery or radiotherapy.
• Post breastfeeding involution.

Malignant.

• Invasive breast carcinoma (ductal and lobular) with retroareolar traction.
• Paget disease of the nipple, ductal carcinoma in situ.
• Inflammatory breast cancer.
• Metastasis to the breast and phyllodes tumour (rare).

Other. Dermatitis and eczema of the nipple, trauma, weight loss and breast atrophy, piercing complications.

Step 1. Establish duration and symmetry. Bilateral long standing inversion without other findings needs no investigation.

Step 2. Acquired retraction needs triple assessment.

• Examination.
• Imaging: bilateral mammography (age 40 and over) and ultrasound of the retroareolar region and axilla; ultrasound first under age 30 to 39 with mammography added for suspicious features.
• Tissue: core needle biopsy (14 gauge, three or more cores) of any mass, distortion or suspicious area, and punch or wedge biopsy of nipple skin changes (Paget disease); fine needle aspiration or culture of an abscess.

Step 3. Breast MRI with contrast for suspected inflammatory or occult cancer when imaging is negative, or for planning in confirmed cancer.

Step 4. Infection: culture of pus, and acid fast stain, GeneXpert and culture for suspected tuberculosis. HIV test in endemic settings when granulomatous or tuberculous disease is possible. Fasting glucose or HbA1c in recurrent infection.

Limitations. Mammography is less sensitive in dense breasts. A negative biopsy that does not match the imaging needs repeat sampling. Retraction from benign duct ectasia and malignancy can look similar on imaging, which is why tissue is needed.

Principles. Diagnose acquired retraction before treating it. Congenital inversion is treated for cosmetic or functional reasons only.

Congenital inversion.

• Reassure. Grade 1 may be managed with suction devices or gentle nipple stimulation (for example a nipple shield or manual traction) before and between feeds.
• Surgical correction (duct preserving or duct dividing techniques) for grades 2 and 3 when the patient wants it; duct division prevents later breastfeeding.
• Avoid piercing.

Periductal mastitis and subareolar abscess.

• Amoxicillin with clavulanic acid 500/125 mg orally every 8 hours for 7 to 14 days (maximum 1.5 g amoxicillin daily; 500/125 mg every 12 hours for CrCl 10 to 30 mL/min; every 24 hours under 10 mL/min); monitor for diarrhoea, rash and liver tests with prolonged courses.
• If penicillin allergic: doxycycline 100 mg orally every 12 hours for 7 to 14 days (maximum 200 mg daily; avoid in pregnancy and breastfeeding; take upright with water) plus metronidazole 400 mg orally every 8 hours (maximum 1.2 g daily; avoid alcohol; monitor for neuropathy with prolonged use).
• Drain abscesses by ultrasound directed needle aspiration repeated every 2 to 3 days, or by incision when the skin is threatened, with cultures.
• Smoking cessation. Total duct excision for recurrent disease or fistula, after the acute episode resolves.

Tuberculous mastitis. Start four drug treatment through the tuberculosis service: isoniazid 5 mg/kg orally daily (maximum 300 mg), rifampicin 10 mg/kg daily (maximum 600 mg), pyrazinamide 25 mg/kg daily (maximum 2 g) and ethambutol 15 mg/kg daily (maximum 1.6 g) for 2 months, then isoniazid and rifampicin for 4 months; give pyridoxine 10 to 25 mg daily; monitor liver tests, visual acuity and colour vision, and uric acid; adjust the dose in kidney impairment, and refer HIV positive patients for specialist care.

Malignancy. Refer to a multidisciplinary breast cancer team. Staging and treatment follow the histology (surgery, systemic and radiation therapy).

Fat necrosis and benign scar. Reassure after imaging and biopsy, and review at 3 to 6 months.

Monitoring. Re-examine at 6 to 12 weeks after treatment of infection. Repeat imaging at 6 and 12 months for lesions classified as probably benign.

Referral and escalation. Breast clinic within 2 weeks for any new retraction. Plastic surgery for correction of congenital inversion. Infectious diseases for tuberculosis or recurrent infection. Oncology for confirmed cancer.

Admission criteria. Sepsis, large abscess, inability to tolerate oral treatment, or suspected inflammatory breast cancer needing urgent assessment.

Discharge and safety netting. Discharge when the cause is benign and treated. Patients return for a new lump, discharge, skin change, fever or a change in the nipple shape.