Breast pain

Breast pain (mastalgia) is pain, tenderness or heaviness felt in one or both breasts. Most cases are benign and hormonal or arise from the chest wall, and breast cancer is an uncommon cause when pain is the only symptom.

Clinical relevance. About two thirds of women report breast pain at some time, and about one in ten has pain severe enough to affect sleep, sexual activity or work. Pain alone carries a cancer yield of well under 5%.

Anatomy and physiology. The breast is innervated by anterior and lateral cutaneous branches of the T3 to T6 intercostal nerves. Pain referred from the chest wall, spine, heart, oesophagus and pleura is frequently felt in the breast.

Mechanisms. Cyclical pain follows cyclic oestrogen and progesterone effects on breast tissue, with water retention and stromal and ductal stimulation. Non-cyclical pain arises from ducts (ectasia, cyst), infection, trauma, fat necrosis, large pendulous breasts, drugs or the chest wall.

Classification.

• Cyclical: begins in the luteal phase, relieved by menstruation, usually bilateral, diffuse and upper outer, and peaks at ages 30 to 45.
• Non-cyclical: constant or intermittent, unrelated to menses, often unilateral and focal, and peaks at ages 40 to 50.
• Extramammary (chest wall and referred): pain reproduced by pressing the chest wall or moving the arm, with normal breast tissue.
• Lactational and puerperal: engorgement, mastitis, nipple trauma and abscess.

Key distinctions. Persistent focal pain in one place beyond 4 to 6 weeks, a new mass, or any skin or nipple change moves the problem from reassurance to triple assessment.

History.

• Site (one or both breasts, diffuse or focal, within the breast or the chest wall), onset, duration, character (burning, sharp, aching, heavy), severity on a 0 to 10 scale and effect on daily life.
• Relation to the menstrual cycle, with a pain diary over 2 to 3 cycles, and relation to pregnancy, breastfeeding, menopause and recent weaning.
• Associated lump, nipple discharge, skin change, fever, breast swelling, axillary swelling and trauma.
• Drugs: combined oral contraceptive, hormone replacement therapy, spironolactone, antipsychotics, antidepressants (sertraline, fluoxetine), digoxin, methyldopa, cimetidine, metoclopramide, domperidone and finasteride.
• Risk factors for breast cancer: age, family history (first degree relatives, BRCA1 and BRCA2), previous breast biopsy with atypia, early menarche, late menopause, nulliparity, previous chest irradiation, alcohol and obesity.
• Caffeine, bra fit and exercise. Cardiac and gastro-oesophageal symptoms, shoulder or neck pain, rash (herpes zoster), cough and pleuritic pain.
• Mood, anxiety and fear of cancer, which often drive consultation.

Examination.

• Both breasts with the patient seated then supine with the arm raised: inspection for asymmetry, skin dimpling, peau d'orange, erythema, nipple retraction, scars and ulceration.
• Palpation of all quadrants, the nipple and the axilla, noting the exact site of tenderness, any mass (size in two dimensions, consistency, mobility, fixity), warmth and fluctuance.
• Chest wall: palpation of costochondral junctions and ribs, the effect of pressing with the arm tensed against the hip (a positive result suggests chest wall pain), thoracic spine and shoulder movement.
• Cardiac, respiratory and abdominal examination when pain is not clearly mammary. Thyroid examination.
• Pregnancy test when the cycle is irregular or overdue.

Red flags.

• A new or persistent breast lump, thickening or area of firmness.
• Bloody or spontaneous unilateral nipple discharge, new nipple retraction or eczema of the nipple.
• Skin dimpling, peau d'orange, rapidly developing breast enlargement or redness over a large area without fever.
• Hard, fixed or enlarging axillary or supraclavicular nodes.
• Focal pain persisting over 6 weeks in a woman over 40, or in any woman with a strong family history.
• Fever, spreading erythema and a tender fluctuant area (abscess).
• Exertional or pressure type left chest pain, breathlessness, sweating (cardiac cause).
• Pleuritic pain, haemoptysis, leg swelling (pulmonary embolism).
• Vesicular rash in a dermatomal distribution.

Special groups. Pregnancy and breastfeeding: pain is common and usually benign, and drug options are limited. Men: gynaecomastia with pain is common in puberty and with drugs, but a firm eccentric mass needs triple assessment. Postmenopausal women with pain are more likely to have a non-cyclical cause, and warrant a lower threshold for imaging.

Cyclical hormonal.

• Premenstrual breast tenderness, fibrocystic change.
• Pregnancy and early lactation.
• Perimenopausal hormonal fluctuation.

Drug related. Hormone replacement therapy, combined oral contraceptive, progestogen only agents, spironolactone, antipsychotics, antidepressants, digoxin, methyldopa, cimetidine, metoclopramide, domperidone, finasteride, ovulation induction.

Breast conditions (non-cyclical).

• Simple and complicated cyst, fibroadenoma, fat necrosis, duct ectasia, periductal mastitis, lactational mastitis, breast abscess, mammary duct fistula.
• Mondor disease (superficial thrombophlebitis of the thoracoepigastric vein), traumatic haematoma, post surgical or post biopsy pain.
• Large pendulous breasts with traction pain, ill fitting bra.
• Breast cancer including inflammatory breast cancer (painful, red, swollen, often without a mass), ductal carcinoma in situ, Paget disease of the nipple.

Chest wall and musculoskeletal. Costochondritis, Tietze syndrome, rib fracture, intercostal muscle strain, fibromyalgia, cervical or thoracic radiculopathy, thoracic outlet syndrome, shoulder disorders. Referred and systemic. Angina and acute coronary syndrome, pericarditis, pulmonary embolism, pleurisy, pneumonia, gastro-oesophageal reflux, oesophageal spasm, cholecystitis, herpes zoster (including pre-eruptive pain), hypothyroidism, hyperprolactinaemia.

Psychological. Anxiety, depression and cancerophobia amplify pain, but are diagnoses of exclusion.

Step 1. Decide whether the pain is breast or chest wall by palpation and the arm pressing manoeuvre, and whether any red flag is present. Exclude cardiac and pulmonary causes when the history suggests them (ECG, troponin, D-dimer or CT pulmonary angiography, directed by clinical probability).

Step 2. First line for pain with a normal breast examination: reassurance and a pain diary. Pregnancy test when relevant. Imaging is not needed for diffuse cyclical pain with a normal examination and a negative family history.

Step 3. Triple assessment (clinical examination, imaging, and tissue sampling when imaging or examination is abnormal) for any focal abnormality, any red flag, or persistent focal pain.

• Age under 30 years: ultrasound first.
• Age 30 to 39 years: ultrasound, with mammography added for suspicious features.
• Age 40 years and over: bilateral mammography (two views) plus ultrasound of any focal area.
• Core needle biopsy (14 gauge, three or more cores) for solid lesions classified as indeterminate, suspicious or malignant. Fine needle aspiration for symptomatic cysts and for palpable abscess collections.

Step 4. Targeted tests. TSH, prolactin and pregnancy test for suspected endocrine causes. Breast MRI with contrast for inflammatory breast cancer with negative imaging, high risk women, implants with suspected rupture, or problem solving. Culture of aspirated pus. Duplex ultrasound for suspected Mondor disease (a cord like tender superficial vein).

Interpretation. Imaging classified as BI-RADS 1 to 2 allows reassurance. BI-RADS 3 (probably benign) needs short interval follow up at 6, 12 and 24 months. BI-RADS 4 or 5 needs biopsy.

Limitations. Mammography is less sensitive in dense breasts, and in women under 40. Ultrasound is operator dependent. A normal imaging result does not explain the pain, which is why a good history and examination remain central.

Principles. Reassure after a normal assessment, which reduces pain in many patients by itself. Treat the cause when one is found. Use drug treatment only for pain that affects daily life after 3 months of simple measures.

Non-drug measures (first line).

• A well fitted supportive bra worn day and night (a sports bra for exercise), weight reduction in obesity, and heat or cold packs.
• Pain diary for 2 to 3 cycles, to confirm cyclical pattern and to measure benefit.
• Review and, where possible, change the offending drug with the prescriber (for example change oestrogen dose or route, or switch the combined pill).
• Evidence for caffeine reduction, low fat diet, vitamin E, vitamin B6 and evening primrose oil is weak and inconsistent.

Analgesia.

• Paracetamol 1 g orally every 6 hours as needed; maximum 4 g daily (3 g daily if weight under 50 kg, malnutrition, alcohol excess or liver disease); monitor liver tests with prolonged use.
• Diclofenac 1% gel: 2 g applied to the painful area up to four times daily for up to 2 weeks (maximum 8 g daily); avoid broken skin and use gloves or wash hands; systemic absorption is low, but avoid in aspirin sensitive asthma and in pregnancy after 28 weeks; review for benefit at 2 weeks.
• Ibuprofen 400 mg orally every 8 hours with food for up to 5 days if topical treatment fails (maximum 1.2 g daily without specialist advice); monitor blood pressure and creatinine; avoid in kidney impairment with eGFR under 30 mL/min, heart failure, peptic ulcer, anticoagulant use and the third trimester.

Specialist drug treatment for severe persistent pain (after 3 months of simple measures, usually from a breast clinic).

• Tamoxifen 10 mg orally once daily for 3 to 6 months (off label for pain); avoid in pregnancy (use reliable non-hormonal contraception), and with a history of venous thromboembolism, stroke or endometrial cancer; monitor menstrual change, hot flushes and thromboembolic symptoms; the benefit often outlasts treatment.
• Bromocriptine 1.25 mg orally at night with food for 1 week, then 2.5 mg twice daily; maximum 5 mg daily for this use; stop at 3 months if there is no benefit; monitor blood pressure and nausea; avoid in uncontrolled hypertension and psychosis.
• Danazol 100 mg orally twice daily during the luteal phase only or continuously, for 3 to 6 months; reserved because of androgenic effects, weight gain and liver toxicity; contraindicated in pregnancy, porphyria and thromboembolism; check liver tests.

Specific causes.

• Lactational mastitis or abscess: flucloxacillin 500 mg to 1 g orally every 6 hours for 7 to 10 days (maximum 4 g daily; reduce the dose in severe kidney impairment), or erythromycin 500 mg orally every 6 hours if penicillin allergic (maximum 4 g daily; monitor QTc with interacting drugs); continue breastfeeding or expression; aspirate abscesses under ultrasound direction.
• Costochondritis or chest wall pain: topical diclofenac 1% gel 2 g up to four times daily (maximum 8 g daily) or ibuprofen 400 mg orally every 8 hours with food (maximum 1.2 g daily) for 1 to 2 weeks, with heat and stretching.
• Herpes zoster: treat promptly with valaciclovir 1 g orally every 8 hours for 7 days (reduce to 1 g every 12 hours for CrCl 30 to 49 mL/min, 1 g every 24 hours for CrCl 10 to 29 mL/min, and 500 mg every 24 hours under 10 mL/min).
• Cardiac or pulmonary causes: needs immediate ECG and troponin, or CT pulmonary angiography directed by clinical probability.

Monitoring. Review at 3 months with the pain diary. Reassess any drug treatment at 3 to 6 months and stop if there is no benefit. Re-examine any patient whose pain evolves or changes.

Referral and escalation. Breast clinic within 2 weeks for any lump, discharge, skin or nipple change, persistent focal pain or abnormal imaging. Urgent same day assessment for suspected abscess with systemic illness. Cardiology or emergency care for suspected acute coronary syndrome. Specialist pain, physiotherapy or psychological services for refractory chest wall pain.

Admission criteria. Sepsis, large abscess needing drainage under anaesthesia, suspected acute coronary syndrome or pulmonary embolism.

Discharge and safety netting. Discharge when the cause is benign and pain is controlled. Patients return if a lump, nipple discharge, skin change or persistent focal pain develops, if fever or redness appears, or if pain does not settle by 3 months.