A. Women Younger Than 30 Years
In women younger than 30 years of age, management of the palpable breast mass depends on the clinician's suspicion for malignancy as well as the results of the initial ultrasound. Masses with a low likelihood of malignancy in the setting of a normal ultrasound do not require any additional radiologic testing. Highly suspicious masses that appear normal on ultrasound should be further evaluated with diagnostic mammography or digital breast tomosynthesis.
Simple cysts can be followed expectantly, whereas a complex cyst may require additional evaluation with fine-needle aspiration and cytology or with biopsy. Cysts can be categorized as probably benign, suspicious, or highly suspicious based on their ultrasound characteristics. Again, if clinical concern for malignancy is high, even women with probably benign findings on ultrasound (or mammogram) should be referred for biopsy. All women with suspicious or highly suspicious findings require biopsy.
B. Women Aged 30–39 Years
For women aged 30–39 years, imaging modalities may include ultrasonography, diagnostic mammography, or digital breast tomosynthesis. Ultrasonography may be more sensitive than mammography in this age group, and so may be the preferred first test. However, women with significant risk factors for breast cancer or a worrisome physical examination should be initially referred for diagnostic mammography or digital breast tomosynthesis.
If the results of the initial ultrasound are normal and there is a low likelihood of malignancy, no additional radiologic evaluation is necessary. Suspicious masses that are detected by ultrasonography require follow-up imaging with bilateral mammography.
Women who undergo diagnostic mammography or digital breast tomosynthesis as the initial imaging test and are noted to have a mass with benign features should have a breast ultrasound performed for correlation. The results of that ultrasound, as well as clinical suspicion, dictate the need for further imaging. When ultrasound findings suggest a benign mass, patients may be monitored clinically or may require short-term radiologic follow-up. In contrast, patients with suspicious findings should be referred for biopsy.
C. Women Aged 40 Years or Older
Diagnostic mammography and digital breast tomosynthesis are the initial tests of choice for women aged 40 years or older with a palpable breast mass. If the mammography or digital breast tomosynthesis results are negative, benign, or probably benign, then additional management depends on clinical suspicion and breast ultrasound results. In the setting of a low clinical suspicion for malignancy, masses with negative ultrasound results can be monitored closely. Conversely, in the setting of worrisome history or physical examination findings, tissue biopsy should be pursued even if both mammogram and ultrasound are normal.
The management of simple cysts in women aged 40 years or older is similar to that in younger women. Solid masses that are classified as probably benign on mammogram and ultrasound should be monitored very closely if clinical suspicion is low but otherwise referred for biopsy. Biopsy is recommended to evaluate any mass that appears suspicious or highly suspicious on ultrasound or diagnostic mammogram.