Objective: To investigate the clinicopathological features, immunophenotypes, and di erential diagnosis of solid papillary carcinoma (SPC) of breast. Methods: Histopathological characteristics and immunohistochemical markers were studied retrospectively and the relevant literatures were reviewed. Results: Seventeen elderly women patients, aged from 39 to 91 (median =72) years, were all with breast mass or nipple discharge. Histologically, the tumor cells showed a solid nest structure. e cells were more moderate and uniform, which were arrayed like water samples, vascular axis and intracellular or extracellular mucus is visible, maybe associated with di erent types of invasive cancer nests. Immunohistochemically, tumor cells expression of ER, PR, CgA, Syn and CD56 were positive. CK5/6, Calponin and P63 of solid nest peripheral myoepithelial were sca ered positive or no expression. Thirteen patients were with negative Her-2 expression, 4 patients Her-2 positive expression was uncertainty, DSISH amplification was not detected with all patients. Conclusion: SPC is a rare breast tumor with unique clinical and pathological features, mostly in the elderly women. Histopathology and immunohistochemical marker are de nite valuable for diagnosis and di erential diagnosis with be er prognosis.