Periductal stromal tumor of the breast with synchronous bilateral breast cancer.

We report on a case of low-grade periductal stromal tumor of the breast with synchronous bilateral breast carcinoma. A 45-year-old woman came to our Hospital because of a palpable mass of the right breast. An approximately 5-cm mass was palpated in the upper right breast. The mammographic and sonographic findings of the palpable mass suggested the possibility of hamartoma. A 1.3-cm, irregular mass with microcalcifications was also detected in the upper outer quadrant of the right breast and a 1.3-cm irregular mass was detected in the upper outer quadrant of the left breast. Core-needle biopsy revealed bilateral breast carcinoma. The patient underwent bilateral breast-conserving surgery, including the excision of the large palpable mass in the right breast. The palpable mass in the right breast was confirmed as low-grade periductal stromal tumor and there were bilateral invasive ductal carcinomas in both upper outer breast quadrants. After surgery, the patient received adjuvant chemotherapy. At 16 months of follow-up, no recurrence was observed.