Invasive Ductal Carcinoma of the Nipple: A Case Report.

We report a very rare case of breast carcinoma which possibly arose from the duct of the nipple and formed a nipple mass. A 71-year-old woman presented with an elastically hard and enlarged right nipple, 3.5x 2.8 cm in size. Mammograms and ultrasonograms suggested a benign tumor of the nipple, but histological examination revealed invasive ductal carcinoma. No Paget's cells were found in the epidermis. Modified radical mastectomy was performed. Both estrogen and progesterone receptors were positive. One of the nine axillary nodes dissected had metastatic foci. To our knowledge, this case is only the second reported case of invasive ductal carcinoma originating from the nipple. Differential diagnosis and histogenesis are discussed.