Clinicopathologic features of intraductal papillary neoplasm of breast: analyses of three cases.

Intraductal papillary neoplasm of breast (IDPN) belongs to a pathological heterogeneous group of diseases, which spans the spectrum of benign, atypical, and malignant. It constitutes less than 10% of benign breast lesions and less than 1% of malignant breast cancers. The majority of IDPNs begins within the ductolobular system of the breast and shows cystic structure with intracystic finger-like projection containing fibrovascular cores. The reasons that made the diagnosis of IDPNs difficult were the proliferation of breast epithelium and the emergence of some illusions. We systematically reviewed 47 cases of breast IDPNs, including 19 cases of intraductal papilloma (IDP), 2 cases of intraductal papilloma with atypical ductal hyperplasia (IDP with ADH), 4 cases of intraductal papilloma with ductual carcinoma in situ (IDP with DCIS), 22 cases of intraductal papillary carcinoma (IDPC), and underwent p63, CD10, SMA, calponin, CK5/6, ER immunohistochemistry Envision staining analysis. This study was focused on three cases which were easy to misdiagnosis and combined the WHO classification to sort out the pathological changes, arousing attention in daily pathological diagnosis.