RESUMO
Occult breast cancer is a rare disease with the primary symptom of enlarged ipsilateral axillary lymph node. At present,it is still difficult to diagnose occult breast cancer. The diagnosis is based on the core needle biopsy and following immunohistochemical staining for the enlarged lymph nodes. If the results support,the diagnosis can be confirmed after the exclusion of other primary tumors. The standard treatment of occult breast cancer is still the mastectomy and axillary lymph node dissection. Neoadjuvant chemotherapy is an independent factor affecting the prognosis,which is also recommended before the oper-ation. Chemotherapy,radiotherapy and endocrine therapy could be chosen based on immunohistochemical results after surgical treatment. The prognosis of occult breast cancer is similar to the other types of breast cancer at the same staging.