Contralateral Axillary Lymph Node Metastasis in Breast Cancer, an Unusual Clinical Scenario: A Case Report andReview of the Literature

Background: Contralateral axillary metastasis (CAM) is a rare entity in patientswith breast cancer which can occur during the primary breast cancer or its follow-up.Different treatment modalities include surgery, radiotherapy, and chemotherapy, butthere is no agreement on them. In our review, we found ۱۲ series with available data, ۸۲patients with synchronous or metachronous contralateral axillary node involvementwith no primary cancer in the contralateral breast.Case Presentation: Our patient was a ۵۰-year-old woman who presented withlocally advanced right breast cancer with no distant metastasis. After treatmentincluding neoadjuvant chemotherapy, MRM, and radiotherapy, her contralateralaxillary lymph node was involved with metastatic carcinoma compatible with ductalcarcinoma of the breast with similar IHC results. Evaluation of the contralateral breastwas negative for occult lesions and metastatic workups were negative for malignancy.We assumed this presentation as aCAMand planned the treatment accordingly.Conclusion: CAM without systemic metastasis might be considered a regionaldisease because in many cases the spread is lymphatic and not hematogenous. The newconcept of lymphatic invasion instead of hematogenous spread has changed the intentof palliative to curative treatment. According to our study, CAM patients were mostlymanaged with chemotherapy (۹۶%), ALND (۴۵%), contralateral breast and axillaryradiation (۳۵%). The prognosis ofCAMis usually poor with a high relapse rate (>۶۰%)and a mortality rate of ۱۵% in our review after ۱۴-۴۳ months follow-up, but it is betterthan the prognosis of the patients with systemic metastasis.