Problem on pathology diagnosis of benign breast lesions LI Da-li, YANG Wen-tao. Department of Pathology, Tumor Hospital, Fudan University, Shanghai 200032, China Abstract This article puts emphasis on a series of benign breast lesions which can easily be misdiagnosed in daily clinical and pathological work. Including breast inflammatory and reactive lesions, benign breast epithelial lesions, benign adenomyoepithelial lesions, benign mesenchymal tumors, benign fibroepithelial neoplasms and florid papillomatosis of the nipple. Benign breast diseases have a variety of histology variation. The diagnosis sometimes is difficult, at this time we should carefully observe them under a light microscope, combined with clinical and general and, if necessary, make further clear diagnosis by immunohistochemical method.