Purpose To discuss the clinical,histopathological characteristics,diagnosis,differential diagnosis and prognosis of malignant intraductal papillary lesions of the breast.Methods 28 cases of malignant intraductal papillary lesions of the breast were analyzed by histology and immunobistochemistry.Clinical and follow-up information was obtained.The published relevant literatures were reviewed.Results All the patients were females with a mean age of 55.7 years.The clinical features were a palpable mass or nipple discharge.28 cases were diagnosed including 22 cases of intraductal papaillary carcinoma,2 cases of encapsulated papillary carcinoma and 4 cases of solid papillary carcinoma.Microscopically,the tumor showed solid and papillary area inside the capsule wall with fine delicate fibrovascular septa.The tumor cells usually displayed low-grade nuclear features.Immunohistochemistry,the tumor cells revealed diffusely strong positive ER and PR in almost all cases and HER-2,CK5/6 were negative positive.All cases were negatiive for CK5/6,p63 and SMA in the celluar nodules.CD56,Syn and CgA were found positively in some solid papillary carcinoma cases.The average positive rate of Ki-67 in tumor cells was 5.3 ％.27 patients were available for follow-up examination from 10 to 79 months and all the patients were alive.Conclusion Malignant intraductal papillary lesions of the breast most occurs in postmenopausal women.The diagnosis should be based on the clinical information,histopathological features and immunohistoehemistry stain due to its diverse histology.The main differential diagnosis is intraductal papilloma.This kind of lesion is a low grade malignant tumor with favorable prognosis.