Due to the fact that capillary vessels provide not only supply of nutritients to the tumor but also represent a gate for lymphogenous and hematogenous metastatic spreading of the tumor, angiogenesis has gained increasing attention in recent years. The aim of the project was: 1. to study number of capillaries in the tumor and its relationship to the metastatic potency and prognosis and 2. to analyse the differences in the quantity of the capillaries between the groups of tumors with or without previously performed aspiration biopsy. 142 cases of breast carcinoma diagnosed at the Fingerland’s Department of Pathology in the years 1997-98 were examined. Endothelial cells were visualized immunohistochemically using an antibody against factor VIII (von Willebrand factor). Capillary vessels were counted at 200x magnification (using eyepiece graticule) in the areas of highest angiogenic activity (hot spots), usually at the periphery of the tumor. The highest microvessel counts (HMC) were correlated with other factors (age, tumor size, grade, nodal status, expression of hormonal receptors, proliferative activity, p53, HER-2/neu). The differences between the tumors with and without previous aspiration biopsy were analyzed. All patients were women aged 31-86 years (median 59). The size of tumors was 4-70 mm (median 20 mm). Sixty cases have been previously examined by fine needle aspiration cytology; 72 cases were node-positive. HMC values varied from 26 to 185 (average 63.9, median 60) per microscopic field (area 0,24 mm 2 ). The HMC was significantly higher in node-positive tumors (median 57,5 versus 66; p=0.036). The capillary vessel counts did not correlate with other parameters examined. Fine needle aspiration cytology does seem to increase the number of intratumoral capillary vessels only for a transitory period. We have also compared HMC/mm 2 in nor- mal breast tissue with counts in carcinoma. Interestingly, the values in normal lobules were significantly higher (median 565 versus 243; p<0.0000001).

        Key words: breast carcinoma - angiogenesis - aspiration cytology - prognosis.