Abstract: Objective To examin the relationship between the expression of proliferating cell nuclear antigen(PCNA), neuregulin-1 and its receptor erbB-2 in acoustic neuroma and the growth characteristics of the tumor. Methods The clinical information of 27 patients with acoustic neuroma were reviewed retrospectively. Paraffin embedded acoustic neuroma samples confirmed by pathology from the 27 patients were included in the study. The expression of PCNA, neuregulin-1 and erbB-2 in acoustic neuroma was determined by immunohistochemistry. Results In all the 27 cases, the positive rate of PCNA was 92.7%(25/27) and the positive rate of neuregulin-1 was 81.4%(22/27). ErbB-2 expressed in none of the cases. There was no significant relationship between the expression of PCNA with gender, age, the side and size of the tumors, but there was significant difference between the expression of PCNA with the course(F=5.011, P=0.015) and clinical growth rate(t=-3.360, P=0.003) of the disease. There was no significant relationship between the expression of neuregulin-1 with gender, age, the side, size and course of the tumors. Although the expression of neuregulin-1 in the tumors of course less than 1 year was higher than that of the course more than 1 year, but the difference was not statistically significant. The expression of neuregulin-1 in the tumors of clinical growth rate less than 10 mm/year was lower than that in the tumors with the clinical growth rate more than 10 mm/year, the difference was not statistically significant. The expression of neuregulin-1 and PCNA had positive correlation(r=0.425, P=0.027). Conclusion PCNA is related with the growth of acoustic neuroma, and reflects proliferation activities of tumor cells in acoustic neuroma. Neuregulin-1 might participate in the biological behavior of acoustic neuroma. As the functional receptor of neuregulin-1, the expression of erbB-2 and its role in acoustic neuroma need further study in more cases. The clinical behavior of acoustic neuroma relates to tumor growth. Some characteristics of acoustic neuroma can reflect the trend of tumor

Key words: neuromas acoustic, proliferating cell nuclear antigen(PCNA), neuregulin-1, erbB-2