CD34 is an antigen present in hematopoietic progenitor cells and endothelial cells. Anti-CD34 antibody is a highly sensitive marker for endothelial cell differentiation and has also been studied as a marker for vascular tumors. However, there are few studies relating it to cervical carcinoma. The aim of this study was to evaluate the association between angiogenesis and the pathoanatomical features of cervical carcinoma using anti-CD34 monoclonal antibody. Sixty-two patients with invasive carcinoma of the uterine cervix in stages Ib-IIa were included. A primary monoclonal antibody specific for CD34 (Anti-Human Hemapoietic Progenitor Cell, CD34 Class II, Clone QBEnd 10, Code M7165, DAKO Corporation) was used in a dilution of 1:25. Microvessel density varied from 4.8 to 20 and was higher in undifferentiated carcinomas (p = 0.03; Mann-Whitney test). Higher microvessel density was associated with squamous cell carcinoma, odds ratio (OR) 8.8 (95% CI: 1.0-76.1), while the presence of lymphatic invasion yielded an OR of 2.6 (95% CI: 0.9-7.4). This study suggested that anti-CD34 antibody reactivity in cervical carcinoma is associated with pathoanatomical features indicative of poorer prognosis.201313-8