[Microdochectomy for elderly patient of ductal carcinoma in situ]. 
We report an elderly patient with ductal carcinoma in situ (DCIS).  The patient was an 82-year-old woman who had spontaneous nipple discharge.  We did not detect the origin of nipple discharge by CT, MRI, mammography, ductal endoscopy, and ultrasonography.  Microdochectomy was performed under the local anesthesia.  A resected specimen led to a diagnosis of a DCIS positive for estrogen receptor and progesteron receptor, and negative for HER2/neu protein expression.  After operation, she was administered aromatase inhibitor.  After three years and two months from the operation, she is well without metastases.  The less invasive operation by local anesthesia is useful for elderly breast cancer patients.  This case suggested that microdochectomy is useful for DCIS in elderly patients.