摘要Objective: We studied the clinicopathological and immunohistochemical features of olfactory neuroblastoma (ONB). Methods: The clinic pathological data and immunohistochemical features of 15 cases with ONB were analyzed ret- rospectively, and the related literatures were reviewed. Results: The tumors were all located in the nasal cavity in 15 cases. According to Kadish's staging system, 7 cases were in stage A, 5 cases in stage B, and 3 cases in stage C. The morphological features showed small round or ovoid tumor cells divided into pieces or trabeculae by connective tissues which were rich in capillaries. The tumor cells had round or oval nuclei and fine chromatins and lack of cytoplasma. Flexner rosette and Homer- Wright rosette were found in some cases. Acidophilic fibrins were composed of cytoplasmic projection among tumor cells. All cases were positive for NSE, Syn, CgA, 1 case was positive for Vimentin, 2 cases were positive for S-100, while CKpan, LCA and HMB45 were all negative. Conclusion: ONB is a type of very rare malignant tumors, which could be diagnosed by pathology, and immunohistochemistry is helpful in the diagnosis and differential diagnosis.