Background: Triple negative (TN) breast cancer is characterized as having a high malignancy potential and a poor prognosis. An understanding of the radiological features of TN DCIS will enable the early detection of intractable TN invasive breast cancer.
Methods: Our cohort of 494 DCIS patients, including 18 TN DCIS cases (3.6%), was diagnosed and treated between January 2006 and November 2009. We reviewed the TN DCIS cases in order to assess mammogram (MMG), ultrasound (US), magnetic resonance imaging (MRI), and pathology findings. Routine diagnostic MMG, US, and MRI were performed before surgery in our institution.
Results: The average age of TN DCIS patients was 54.2 years (40-73). MMG findings were as follows: no abnormal findings (n = 4), masses (n = 3), focal asymmetric density (n = 2), architectural distortion (n = 5), and calcifications (n = 4). US findings included low echoic masses (n = 17) and architectural distortion (n = 4). MRI findings (two patients did not undergo this examination) included mass (n = 6) and non-mass-like enhancements (n = 10). The average lesion measured 3.3 cm in diameter (0.5-8.5 cm). The histological findings were non-comedo type (n = 9) and mixed type including some comedo components (n = 9). Notably, our study revealed that only 22% of TN DCIS cases were detected via mammographic abnormal calcifications. This percentage was less than in non-TN DCIS cases. TN DCIS cases were detected mainly because of masses or asymmetry. US and MRI findings of TN DCIS revealed the same features considered to be common DCIS findings.
Conclusion: We diagnosed TN DCIS in 3.6% of our cohort including 494 DCIS patients. Incidences of TN DCIS with mammographic abnormal calcifications were fewer than those of non-TN DCIS cases.