Ganglios axilares contralaterales: enfermedad sistémica versus metástasis de un cáncer de mama oculto. Descripción de dos casos clínicos: el seguimiento es la clave para el diagnóstico

Metastases to the contralateral axillary lymph nodes in breast cancer patients are uncommon. Involvement of the contralateral axilla is a manifestation of systemic disease (stage IV) or a regional metastasis from a new occult primary (TxN1, stage II) The uncertain laterality of the cancer responsible for these metastases complicates overall disease staging and is a management dilemma for clinicians. Only a significant difference in estrogen and progesterone receptor levels or HER2/neu overexpression could ascertain the diagnosis. Two women who developed contralateral axillary metastases (CAM), but did not have evidence of systemic disease were identified. Presumption diagnosis and treatment of the CAM were different in both cases: metastatic breast cancer and radical radiotherapy in the first patient and bilateral breast cancer with axillary lymph node dissection in the second patient. After follow up of both cases, different final diagnosis were made: primary contralateral breast cancer in the first case, and liver metastases in the second one.