Sentinel Lymph Node Biopsy Performed for HER2 Positive Axillary Accessory Breast Cancer after Neoadjuvant Chemotherapy—A Case Report—

Abstract

Although axillary lymph node dissection has been a standard therapy for axillary accessory breast cancer, sentinel lymph node biopsy is recently performed in some cases. We have experienced a case of HER2 positive axillary accessary breast cancer in which local partial excision with sentinel lymph node biopsy was performed after neoadjuvant chemotherapy to omit axillary lymph node dissection. The case involved a 61-year-old woman who was referred to our hospital because she had been aware of a right axillary tumor for 2 months. Close examination led to the diagnosis of accessory breast cancer (cT1N0M0 Stage I, HER2 positive) of the right axilla, and we performed neoadjuvant chemotherapy followed by local partial excision with sentinel lymph node biopsy. Intraoperative frozen section diagnosis was conveyed to us reporting metastasis negative, so that axillary lymph node dissection could be omitted. Pathological study demonstrated a 3-mm sized residual of invasive cancer component. Following the adjuvant systemic therapy with T-DM1, the patient has experienced no disease recurrence.