AIM: To study the expression of tumor-infiltrating dendritic cells(TIDC)in retinoblastoma(Rb)and its prognostic significance.

METHODS: The expression of tumor-infiltrating dendritic cells was examined by immunohistochemical staining(S-P method), using CD1a mouse monoclonal antibody in Rb tissues of 31 cases.

RESULTS:The expression of CD1a⁺ cells was found in tumor samples of 23 cases(74.2%)among the total 31 cases. The rates of positive CD1a expression in well-differentiated type was 77.8%(7/9)and in undifferentiated type cancer tissues was 75%(15/20), respectively(P>0.05). The rate of spontaneous regression type was 50%(1/2).

CONCLUSION: There was no correlation between the number of CD1a⁺ cells and tumor grade in Rb. It is difficult to identify whether TIDC was good indicator in assessing tumor prognosis.