Adenoma of the nipple projecting out of the nipple: curative resection without excision of the nipple

BACKGROUND: Adenoma of the nipple is a rare breast tumor that is often mistaken clinically for Paget’s disease and misinterpreted pathologically as invasive ductal carcinoma. CASE REPORT: We report herein a distinctive case of adenoma of the nipple projecting out of the nipple. In the current case, we were able to perform curative resection through a periareolar incision similar to a microdochectomy without excision of the nipple. The diagnosis of adenoma of the nipple was confirmed histopathologically. CONCLUSION: Although the tumor was found on top of the nipple, curative tumor resection without excision of the nipple was possible and the nipple was completely preserved. Adenoma of the nipple is a benign tumor, and thus the diagnosis of adenoma of the nipple must be confirmed so that unnecessary surgery can be avoided.