Differential Diagnosis of Pain in the Breast (Mastalgia / Mastodynia)

Key point: Breast pain is an uncommon symptom of breast cancer - it occurs in only ~7% of breast cancer patients. However, cancer must remain in the differential, especially with noncyclic, unilateral, or localized pain.

Classification Framework

I. Cyclic Breast Pain

1. Fibrocystic Change (most common cause)

• Exaggerated hormonal response of breast stroma and epithelium to estrogen/progesterone
• Bilateral, premenstrual cyclic mastalgia with tender, nodular, lumpy breasts
• Most prominent in the upper outer quadrants
• Common in the 4th and 5th decades; resolves at menopause
• Sabiston Textbook of Surgery

2. Premenstrual Breast Edema (Physiologic)

• Normal cyclic intralobular edema during the late luteal phase
• Due to fluid accumulation under progesterone influence
• Bilateral breast engorgement and pain; resolves with menstruation
• Sabiston Textbook of Surgery

3. Breast Cysts

• Simple cysts can cause cyclic or noncyclic pain
• Arise from dilatation of lobules and terminal ductules
• Common in women >35 years; influenced by ovarian hormones
• Aspiration is both diagnostic and therapeutic
• Sabiston Textbook of Surgery

4. Hormonal/Exogenous Hormone Use

• Oral contraceptive pills, hormone replacement therapy (HRT)
• Postmenopausal women on HRT can develop new cysts and cyclic pain
• Sabiston Textbook of Surgery

II. Noncyclic Breast Pain

5. Ruptured/Tense Breast Cyst

• Sudden localized pain, often in one quadrant
• Can be felt as a palpable tender mass
• US confirms; aspiration is curative
• Robbins, Cotran & Kumar

6. Fibroadenoma

• Usually painless but can cause localized discomfort
• Most common benign tumor in young women (<35 years)
• Round, rubbery, mobile, well-demarcated mass
• Robbins, Cotran & Kumar

7. Duct Ectasia / Periductal Mastitis

• Subareolar pain, often burning or aching
• May present with nipple discharge, nipple retraction, or subareolar mass
• More common in smokers, overweight women, perimenopausal/postmenopausal
• Pathogen: Staphylococcus/Streptococcus - treat with dicloxacillin or cephalexin
• Tintinalli's Emergency Medicine

8. Mastitis (Puerperal and Non-Puerperal)

• Localized breast pain with erythema, warmth, swelling, fever, malaise
• Puerperal: first weeks postpartum; associated with breastfeeding
• Non-puerperal: associated with diabetes, obesity, smoking
• Organisms: Staphylococcus aureus (including MRSA), Streptococcus
• Tintinalli's Emergency Medicine; Current Surgical Therapy 14e

9. Breast Abscess

• Severe localized pain, fluctuant swelling, systemic fever and malaise
• Complication of untreated mastitis
• US-guided needle aspiration is first-line; IV antibiotics if severe
• MRSA accounts for up to 20% of cases
• Tintinalli's Emergency Medicine

10. Fat Necrosis / Traumatic Injury

• History of direct trauma, surgery, or radiation
• Localized, firm, sometimes painful area
• Can mimic carcinoma on imaging; biopsy may be needed
• Sabiston Textbook of Surgery

11. Mondor's Disease (Superficial Thrombophlebitis)

• Rare; painful cord-like thickening along the anterolateral chest wall or breast
• Due to thrombophlebitis of superficial thoracic veins
• Self-limiting; treat with NSAIDs

12. Inflammatory Breast Cancer

• Must NOT miss: presents as painful, warm, erythematous, enlarged breast with peau d'orange skin changes
• No palpable mass may be present initially - can mimic mastitis
• Failure to respond to antibiotics is the key red flag
• Prompt mammography and skin biopsy required
• Tintinalli's Emergency Medicine

13. Breast Cancer (Non-inflammatory)

• Pain is an uncommon presentation (~7% of cases)
• Noncyclic, localized, persistent - especially with associated mass, skin changes, or nipple retraction
• Sabiston Textbook of Surgery

14. Hidradenitis Suppurativa

• Recurrent painful abscesses along the inferior breast fold and axillae
• Chronic obstruction of sweat glands; polymicrobial colonization
• Scarring and sinus tracts with recurrence
• Tintinalli's Emergency Medicine

15. Skin Conditions Affecting the Breast

• Herpes zoster: dermatomal burning pain; vesicular rash
• Contact dermatitis, intertrigo (under pendulous breasts)

III. Extramammary (Referred) Pain

16. Costochondritis / Tietze Syndrome

• Tenderness at the costochondral junctions (ribs 2-5)
• Sharp pain worsened by palpation of the chest wall
• Most common cause of extramammary breast pain
• Reproduced by pressing on the costochondral junction

17. Scapulothoracic Bursitis (Referred Pain)

• Afferent signals from the shoulder converge with intercostal nerves at the dorsal horn
• Referred pain along intercostal distribution to axilla, breast, and arm
• Can be cyclic or noncyclic
• Trigger point injection at the medial scapular border is both diagnostic and therapeutic
• Sabiston Textbook of Surgery

18. Intercostal Nerve Irritation

• Irritation of T3-T5 intercostal nerves causes bilateral breast/nipple pain
• Pain may radiate to the axilla or scapula
• Tintinalli's Emergency Medicine

19. Cervical/Thoracic Radiculopathy

• Nerve root compression (C5-T5) can produce pain radiating to the breast
• Associated with neck or back symptoms, worsened by movement

20. Cardiac Disease

• Angina pectoris or myocardial infarction can occasionally present as left breast pain
• Important in women who frequently present atypically
• Must consider in older women, diabetics, or those with cardiovascular risk factors

21. Gastroesophageal Reflux / Esophageal Spasm

• Substernal or left-sided chest/breast pain, often burning
• Worse after meals, relieved by antacids

22. Pulmonary Causes

• Pleuritis, pneumothorax, or pulmonary embolism can cause pleuritic breast-region pain
• Worsened by inspiration; associated respiratory symptoms

Summary: Key Distinguishing Features