A case of gestational breast cancer diagnosed in the early stage by ultrasound examination

Abstract

The patient was a 38-year-old woman. Breast cancer screening at 5 weeks of pregnancy by breast ultrasound revealed a mass measuring 8 mm in diameter in the left breast at the 1 o'clock position, and the patient was referred to our department. She visited our department first when she was 10 weeks pregnant. Breast ultrasound showed a well-defined, rough, irregular mass measuring 86x8 mm in size at the 1 o'clock position in the left P area. A core needle biopsy revealed the diagnosis of invasive ductal carcinoma of the breast. The patient wished to continue her pregnancy, so that we planned to wait until the second trimester for the surgery. A left mastectomy with sentinel node biopsy was performed at 20 weeks of gestation, and the postoperative histopathological diagnosis was invasive ductal carcinoma of the breast, pT1b (10mm), pN 0, histological grade II, Ly0, V0, ER positive (100%), PR positive (90%), HER2 negative (1+), ki 67 22.4%. The patient delivered by normal vaginal delivery at 36 weeks of gestation and was started on tamoxifen. The child showed good growth milestones after delivery, and until date, has shown no evidence of growth retardation. Breast ultrasonography is a useful modality for early diagnosis of breast cancer even in the presence of physiological changes associated with pregnancy, but the drawbacks of this screening tool under these circumstances (decreased sensitivity of cancer screening, increased false positives, lack of evidence) should be fully communicated in advance to the examinee. In the treatment of gestational breast cancer, it is important to decide on a treatment plan considering the number of weeks of pregnancy at the time of diagnosis, the breast cancer subtype, the clinical cancer stage, and the patient’s wishes.