A CASE OF NONINVASIVE DUCTAL CARCINOMA WITH APOCRINE METAPLASIA

Apocrine carcinoma is an uncommon, poorly characterized type of breast tumor. We experienced a case of apocrine carcinoma without infiltration that did not belong to the general rules. A 57-year-old woman was seen at the hospital because of an abnormal echoic shadow in her left breast pointed out at a medical checkup for breast cancer. The tumor was palpated as a hard mass (0.8×0.7cm) with ill-defined margin under the areola. An irregular hypoechoic lesion under the areola was observed by ultrasonography. Mammography did not reveal a tumor shadow. Diagnosis of aspiration biopsy cytology was breast cancer for class V. Breast conserving surgery (Bp (2.0cm)+Ax) with radiation therapy was performed. Histopathological examination revealed intraductal carcinoma with fully apocrine metaplasia. Apocrine carcinoma is classified as invasive carcinoma according to histological classification of breast tumor by the Japanese Breast Cancer Society. Fundamentally, the name of “noninvasive apocrine carcinoma” is proper for this case. But, following the general rules, it should be classified as noninvasive ductal carcinoma, apocrine type.