Two cases of ductal adenoma of the breast.

We encountered two cases of ductal adenoma of the breast. In the first case, a 32-year-old woman presented with a two-year history of a left breast lump. Previous ultrasonography had demonstrated three tumors which were thought to be most likely fibroadenoma. On excisional biopsy of the largest , intraoperative pathological examination of frozen sections was suspicious for ductal carcinoma with a differential diagnosis of intraductal papilloma or intraductal papillary carcinoma. Ductal adenoma was diagnosed after pathological examination of the permanent sections. The second case was a 64-year-old woman who presented with a hard lump in her left breast. Mammography and ultrasonography demonstrated images typical of carcinoma. Aspiration biopsy cytology (ABC) repeated twice was reported as " indeterminate". Excisional biopsy was later done. Ductal adenoma (sclerosing papilloma) with hemorrhagic infarction was diagnosed. It is noteworthy that ductal adenoma have clinical and histopathological features that should be differentiated from carcinoma, especially when the tumor is accompanied by secondary changes such as hemorrhage or infarction.