Ectopic breast tissue usually develops along the mammary ridge. The incidence of this anomaly has been reported as high as 6%. Malignant development is rare. A case of carcinoma of aberrant breast tissue, located in the axilla is described. Mammographies of the ectopic breast performed few years before the diagnosis of carcinoma are presented and also those done for the diagnosis of the tumor. A literature study was performed on carcinoma and ectopic breast tissue. Considering high frequence of node involvements for these cases, the optimal therapeutic strategies are discussed.