Microvascular structure of benign and @entity694 in XXXX .

@entity1 @entity5 @entity1412 @entity189 @entity652 @entity694 @entity420
Studies of experimental @entity5 in rodents indicate that there are morphological @entity5 microcirculation compared to normal tissues. The aim of this study was to examine the structure of the microvasculature in benign and malignant @entity694 in @entity1 using microvascular casting techniques. There were 15 @entity420 , four @entity652 , and three specimens from @entity1 with @entity1412 ( @entity1412 ). A cast of the microvessels of these @entity5 was prepared by intraarterial administration of acrylic resin (Mercox) and the cast examined by scanning electron microscopy. Quantitative measures of the microvasculature were obtained from histological sections using stereological techniques in four @entity189 , two @entity652 , and 12 @entity652 from @entity1 with @entity1412 . Vascular casts of benign colonic @entity652 showed that the microvasculature had a similar organization to normal colon. However, capillaries and venules were elongated and had increased diameters compared to normal. In @entity652 greater than 3 mm in diameter, there was an increased density of microvessels in the spaces between @entity5 cells. Vascular casts of @entity694 were characterized by a disorganized structure and increased density of microvessels. The organization of microvessels within @entity189 had a similar overall pattern to normal colon. However, the increased number and density of microvessels resulted in formation of nodular clusters of capillaries, formation of "sheets" of frequently anastomosing capillaries, or almost complete packing of the interstitial spaces of the @entity5 by capillaries in places. Most capillaries had a long and tortuous course and numerous capillary sprouts were identified. Tumor microvessels had greater mean diameters than normal. Extravasation of resin from microvessels in @entity189 was frequently seen. The vascular volume of @entity189 (23.1% +/- 12.2), @entity652 (16.3% +/- 3.4), and @entity652 > 3 mm diameter in @entity1 with @entity1412 (17.7% +/- 3.0) were significantly greater than in normal colon (11.0% +/- 4.2). This study indicates that there is an increased vascular density in benign and @entity694 compared to normal colon. The presence of profusely anastomotic microvessels and frequent capillary sprouts is evidence of active neovascularization and suggests control of @entity5 growth could be achieved by modifiers of angiogenesis.
