47- year old patient presented for a bilateral screening mammogram. At the time of her appointment she was offered a screening ultrasound due to dense breast tissue. Mammography was performed with digital breast tomosynthesis and C-view which noted dense breast tissue; no suspicious masses or calcification were seen in either breast.
Diagnosis: Invasive mammary carcinoma
Screening ultrasound was performed and demonstrated a 3cm irregular, hypoechoic mass in the 12:00 position of the right breast. An ultrasound guided needle core biopsy of the mass was performed. Needle core biopsy of the right breast lesion was performed under ultrasound guidance revealing invasive mammary carcinoma. Two abnormal-appearing enlarged lymph nodes were also noted in the axilla on ultrasound and one was biopsied revealing metastatic mammary carcinoma. Both lesions biopsied were mammographically occult in this patient with dense breast tissue.
Mammography is the gold standard for detecting breast cancers. Digital Breast Tomosynthesis can increase breast cancer detection at a range of 1.2 to 2.7 per 1,000 screenings. Ultrasound, when used as a screening tool, can detect breast cancers that are not visualized on mammography. In one ongoing study, participants that had normal 2D mammography and had dense breast tissue underwent a tomosynthesis mammogram and an ultrasound. Tomosynthesis was shown to yield 4.0 cancers per 1,000 screenings while ultrasound was shown to yield 7.1 cancers per 1,000 screenings in women with dense breast tissue and normal mammograms.
Tagliafico AS, Calabrese M, Mariscotti G, et al. Adjunct Screening With Tomosyntheses or Ultrasound in Women With Mammographically-Negative Dense Breasts: Interim Report of a Prospective Comparative Trial. Journal of Clinical Oncology. 2016;34:1882-1888.