What are the likely causes of breast pain in a 20-year-old woman with a normal ultrasound?

Causes of Breast Pain in a 20-Year-Old Woman with Normal Ultrasound

In a 20-year-old woman with normal ultrasound, breast pain is most likely cyclical mastalgia related to hormonal fluctuations during the menstrual cycle, which accounts for 70% of breast pain cases and requires no further imaging or intervention beyond reassurance. 1

Primary Etiology: Cyclical Mastalgia

The most common cause is cyclical breast pain, which is hormonally driven, typically bilateral or diffuse, and waxes and wanes with the menstrual cycle. 1, 2 This represents the overwhelming majority of breast pain in young women and is not associated with malignancy. 1

• Cyclical mastalgia occurs in up to 70% of women with breast pain and typically affects women in their third decade of life. 1
• The pain is often accompanied by swelling and breast tenderness that varies with hormonal fluctuations. 1
• The etiology involves disturbances in hypothalamic control, abnormal hormonal responses, altered end-organ sensitivity, and disorders of lipid metabolism or fatty acid levels. 1

Secondary Causes to Consider

Noncyclical Mastalgia

Noncyclical pain accounts for 25% of cases and is typically unilateral, more focal, and located in the subareolar area or lower inner breast. 2

• This type is predominantly inflammatory rather than hormonal in nature. 2
• Twenty-five percent of noncyclical pain cases involve duct ectasia with periductal inflammation, characterized by continuous burning pain behind the nipple, often associated with heavy smoking. 1
• Women with large breasts may experience noncyclical pain simply related to breast size, often accompanied by neck, shoulder, and back pain. 1

Medication-Related Causes

Hormonal medications and certain antidepressants are frequently implicated in breast pain. 1

• Oral contraceptives, hormone replacement therapy, and infertility treatments can cause breast pain and tenderness. 1
• Selective serotonin reuptake inhibitor (SSRI) antidepressants are specifically associated with mastalgia. 1

Extramammary (Referred) Pain

Ten to fifteen percent of "breast pain" originates from non-breast sources. 1, 2

• Musculoskeletal causes include costochondritis (Tietze syndrome), pectoral muscle strains, and entrapment of intercostal nerves. 1, 2
• Spinal nerve root syndrome from cervical or thoracic degenerative changes can refer pain to the breast. 1
• Other sources include coronary ischemia, esophageal disease, pulmonary conditions, and gallbladder pathology. 1

Important Clinical Reassurance

The normal ultrasound is highly reassuring, as cancer is an extremely rare cause of breast pain in this age group. 1, 3

• In women under 30 with cyclical breast pain as the only complaint, prospective studies found no malignancy. 1
• The risk of cancer in women presenting with breast pain as the only symptom ranges from only 1.2-6.7%. 2
• Breast pain alone, particularly when cyclical and diffuse, is not associated with malignancy. 1

Common Misconceptions to Avoid

There is no convincing scientific evidence that caffeine intake affects breast pain, despite widespread belief to the contrary. 1, 2

• Studies show no direct relationship between mastalgia and fibrocystic changes or total-body water retention. 1
• While breast pain can be associated with diffuse palpable nodularity, there is no relationship between the extent of nodularity and pain severity. 1

Management Implications

For this patient, reassurance alone resolves symptoms in 86% of mild cases and 52% of severe cases. 2

• Simple non-pharmacological measures are first-line: well-fitted supportive bra, regular physical exercise, and over-the-counter NSAIDs for symptomatic relief. 2
• No additional imaging beyond the normal ultrasound is indicated for diffuse, nonfocal, or cyclical breast pain. 1, 2
• Most cyclical mastalgia cases (14-20%) resolve spontaneously within 3 months. 4