A Case of Ipsilateral Breast Cancer Recurrence with Contralateral Axillary Lymphatic Drainage Visualized by Indocyanine Green Fluorescence Imaging

Abstract

The patient was a 72-year-old woman. At age 58 years, she underwent partial mastectomy with axillary lymph node dissection for cancer of the left breast, followed by postoperative treatment and outpatient follow-up, leading to routine surveillance. Fourteen years after surgery, she noticed a mass in the ipsilateral breast and visited our hospital for evaluation. Detailed examination showed ipsilateral breast tumor recurrence in the preserved breast, accompanied by contralateral axillary lymph node metastasis. The histological type and subtype differed from those of the initial breast cancer, so the lesion was considered a new primary breast cancer. Since the systemic workup showed no evidence of distant metastasis, the contralateral lymph node metastasis was interpreted as regional lymphatic spread resulting from altered lymphatic drainage due to the initial surgery. Left mastectomy and right axillary lymph node dissection were performed with curative intent. Intraoperative lymphatic mapping using indocyanine green (ICG) fluorescence demonstrated that lymphatic flow from the left breast to the right axilla directly reached the dissected lymph node. In cases of ipsilateral breast cancer recurrence accompanied by contralateral lymph node metastasis, ICG fluorescence imaging may be useful for directly visualizing lymphatic flow intraoperatively and for supporting curative resection.