Invasive papillary carcinoma of the breast:clinicopathological analyses of 12 cases

QIU Yuhuan; HUANG Qian; WEI Roufan; JIAO Wanting; ZHANG Weixuan; ZHANG Wei

doi:10.3969/j.issn.1007-8096.2025.08.010

Abstract：Objective To explore the clinical pathological features,differential diagnosis,treatment,and prognosis of invasive papillary carcinoma(IPC)of the breast.Methods Clinical,imaging,and pathological data from 12 patients with breast IPC were collected and analyzed for their clinical pathological features and immunohistochemical results.Results All patients were female with a median age of 60 years(range,41-75 years).Clinically,all patients presented with painless breast masses,most of which(8/12)were located in the upper outer quadrant of the breast.Pathological examination revealed that five cases were pure IPC,and seven cases were mixed IPC.The tumors showed expansile infiltration,with the absence of basement membrane around the nests of cancer cells.The cancer cells were arranged in various papillary patterns around fibrovascular cores,with most being of low to intermediate nuclear grade(9/12)and a minority being of high nuclear grade(3/12).Immunohistochemical staining for p63 and CK5/6 showed the absence of myoepithelium around the papillary cores and expansile infiltrating nests.The molecular subtypes were predominantly Luminal B(6/12),followed by Luminal A(3/12)and triple-negative(3/12).Eleven patients underwent modified radical mastectomy,and one patient underwent breast-conserving surgery.Follow-up ranged from 4 to 144 months.Two patients were lost to follow-up(one of whom had chest wall recurrence),one patient died,and nine patients were disease-free survivors.Conclusion IPC is a rare papillary neoplasm.Diagnosis requires the combination of morphological features and immunohistochemical markers to differentiate it from other primary and metastatic papillary tumors of the breast.Adhering to a multimodal differential diagnosis protocol can improve the accuracy of pathological diagnosis of IPC.