Invasive Ductal Carcinoma of the Breast Presenting With Contralateral Axillary Lymph Node Metastasis: A Case Report.

This is a case of a 71-year-old Caucasian female presenting with invasive carcinoma of the breast with contralateral axillary lymph node metastasis. This unique presentation presents clinicians with difficulty staging and, therefore, predicting patient prognosis. This patient had a history of right ER/PR positive HER2 negative stage 1 breast cancer s/p lumpectomy with sentinel lymph node biopsy and radiation plus tamoxifen x6 months in 2017. She is now presenting with a recurrence of right breast cancer along with additional metastatic disease to the contralateral (left) axilla. She was treated with a skin-sparing mastectomy along with a contralateral lymph node dissection. A negative sentinel lymph node was seen, representing the dilemma of non-contiguous metastatic spread. Histological pathology of the right breast masses revealed multifocal invasive carcinoma of no special type (ductal), along with two of five left axillary lymph nodes positive for metastatic mammary carcinoma. No right-sided sentinel node was identified. The right breast lesions and the left axillary lymph node metastases are all morphologically similar and showed strong ER expression, the results of which are compatible with spreading to the contralateral axilla.