Aberrant breast tissue is usually found in proximity to the normal breast, that is, in the axillary, sternal or clavicular regions. Carcinoma occurs more frequently in the aberrant tissue of the axilla than the extra-axillary site though the overall incidence of tumors of aberrant breast tissue is low. To our knowledge, studies regarding the carcinoma of aberrant breast tissue of the extra-axillary site have been reported rarely. Here we report a recent case of carcinoma originating from the extra-axillary aberrant breast tissue, presenting as a subcutaneous nodule on the right upper anterior chest wall. It is suggested that subcutaneous nodules of uncertain origin around the periphery of the breast should be suspected for breast carcinoma as a differential diagnosis and treated properly.