The management of contralateral axillary sentinel lymph nodes detected by lymphoscintigraphy in a patient of breast cancer that had never undergone breast related medical treatment

In breast cancer, lymphoscintigraphy-based sentinel lymph node biopsy examinations usually show lymphatic drainage to the ipsilateral axilla, and sometimes to the extra-axillary regions. Drainage to the contralateral axilla is rarely observed in patients that have never undergone any medical treatment involving their breasts. We experienced a case of breast cancer in which bilateral sentinel lymph nodes were detected by lymphoscintigraphy in a patient that had never undergone any medical treatment involving her breasts. Here, we report a rare case and review the clinical and pathological features of several reported cases. In addition, we discuss the necessity of subjecting contralateral sentinel lymph nodes to a biopsy examination.