[A Case of Adenoid Cystic Carcinoma of the Breast].

Primary adenoid cystic carcinoma(ACC)of the breast is a rare type of breast cancer. A 53-year-old woman with a right breast mass was examined at our institute. Ultrasonography showed 12.5×10.3×8.4 mm sized an ill-defined hypoechoic mass at zone C of the right breast. Pathological examination of core needle biopsy revealed atypical cells with solid and cribriform growth pattern. Computed tomography did not reveal lymph node metastases or distant metastases. The preoperative diagnosis was Stage ⅠA(cT1cN0M0, ER/PgR/HER2=-/-/1+)invasive ductal carcinoma or ACC. Surgery consisted of breast-conserving surgery and sentinel node biopsy. Pathological examination of the excised specimen revealed a so- called adenoid cystic pattern, so the final diagnosis was Stage ⅠA(pT1cN0M0, ER/PgR/HER2=-/-/1+)ACC. After 1 year of observation without adjuvant treatment, there has been no recurrence.