Abstract: Abstracts: Objective To study the pathological characteristics of breast infiltrative ductal / lobular mixed carcinoma(IDC-L), infiltrative lobular carcinoma(ILC) and infiltrative ductal carcinoma(IDC). Methods From September 2011 to September 2020,254 breast cancer patients were selected, Among them, there were 18 cases of IDC-L, 20 cases of ILC and 216 cases of IDC. The prognosis of the three groups of patients was observed. Results IDC- L, ILC and IDC patients had significant differences in age, tumor size, multicentric lesions, vascular invasion, HER2 status, Ki-67 expression. IDC-L patients had younger onset age, more tumor diameter>2.0 cm, while IDC patients had less multicentric lesions and vascular invasion, while HER2 positive rate and Ki-67 high expression ratio in IDC-L and ILC patients were lower than IDC, the difference was statistically significant(P<0.05). Age, climacteric state, tumor size, lymph node state, multicentric lesions, lymphatic vessel invasion, HER2 state and Ki-67 expression were all the influencing factors of clinic pathological differences. Breast cancer-free interval and overall survival were related to tumor size, lymph node status, lymphatic vessel invasion and Ki-67 expression (P<0.05). Conclusion In breast cancer patients, the clinicopathological characteristics of ILC and IDC-L are similar to each other, but there are obvious differences among ILC, IDC-L and IDC. The breast cancer patients can be differentiated clinically and treated better.

Key words: Key words: Invasive ductal/lobular mixed carcinoma of breast, Invasive lobular carcinoma, Invasive ductal carcinoma, Pathology, Prognosis