Axillary lymph node metastases as the sole clinical site of occult breast carcinoma

Patients without evidence of breast disease, who present with axillary lymph node metastases, consistent with breast origin, comprise a diagnostic and therapeutic dilemma. We describe such a case of a 47-year-old female, who complained of swelling and pain of the left axilla, but no breast mass was palpable. Although histology identified a metastatic adenocarcinoma in the lymph nodes, numerous tests failed to detect the primary tumor. Immunohistochemistry showed that the resected lymph nodes were positive for both estrogen and progesterone receptors, CEA and Gross Cystic Disease Fluid Protein 15 (GCDFP-15), suggesting the breast as the site of the primary tumor. Left modified radical mastectomy was performed. Pathology revealed an invasive ductal carcinoma, 12 mm in size. The patient received adjuvant chemotherapy and radiation therapy. She is currently being treated with tamoxifen and is well without evidence of disease 2 years after surgery.