We report the case of a 42-year-woman treated for an appendicular carcinoid tumor with bilateral ovary metastases and mesenteric node involvement. After a systematic mammography, an infraclinical lesion of the breast was detected. Mammographic and echographic images revealed nodular mass with possibly malignant features. Fine-needle aspiration biopsy indicated malignancy. The definitive diagnosis of breast metastasis of a carcinoid tumor was made by biopsy. This case is related to 14 previously published cases. The authors emphasize the importance of making a precise histological diagnosis to avoid overtreatment of a metastatic lesion.