Clinical and pathological characteristics of occult breast cancer and review of the literature

Purpose: Occult breast cancer is defined as axillary metastasis without clinically and/or radiologically evident primary tumor. In female patients presenting with isolated axillary nodes with adenocarcinoma, the most likely primary cancer is an invasive breast carcinoma. Herein we present our experience over this issue, together with a brief review of the literature about this clinically challenging condition. Methods: We retrospectively analyzed 1215 consecutive breast cancer patients treated at our clinic between 2004- 2010. Four of these patients presented with axillary nodal metastasis without clinical and radiological evidence of a primary breast tumor. Results: The incidence of occult breast cancer in our clinic was 0.32%. Median follow-up was 8 months. All patients were alive and remained free of disease at the end of the follow-up period. Conclusion: The prognostic factors for occult breast carcinoma are similar to that of its overt counterpart. The number of axillary lymph node involved and the hormone receptor status are considered significant prognostic predictors. Further studies with randomization and longer followup are needed for the establishment of a safe management plan.