Axillary Metastasis with Occult Primary Breast Cancer

Abstract

The identification of an axillary metastasis in the absence of a primary breast cancer can pose a diagnostic and therapeutic dilemma. The clinician should first use more sensitive imaging modalities, such as breast magnetic resonance imaging, to attempt to find the primary index lesion. If the primary cancer remains occult and the molecular markers are consistent with a breast origin, then the recommended treatment includes multimodality therapy including surgery, chemotherapy/endocrine treatment, and radiation. Historically, the modified radical mastectomy was the standard of practice. Recently, in the era of improved adjuvant therapies, breast-conserving surgery with irradiation is also being considered. Multiple retrospective reviews have shown no difference in survival or recurrence with these two surgical pathways. However, due to the rare nature of this clinical presentation, no multiinstitutional or prospective clinical trial data are available. Key words: axillary lymph node dissection, axillary metastasis, breast cancer, breast conservation, local recurrence, occult primary tumor, radiotherapy