RESUMEN
<p><b>OBJECTIVE</b>To investigate relationship between expression of inducible nitric oxide synthase (iNOS) and proliferative potency of endothelium in hemangioma (HM).</p><p><b>METHODS</b>Immunohistochemical staining was used to detect expression of iNOS and Ki-67 protein in 49 cases of HM and 29 cases of vascular malformation (VM).</p><p><b>RESULTS</b>Expressive rate of iNOS and Ki-67 protein of 49 cases of HM was 38% and (10.98 +/- 7.93)%. Expressive rate of iNOS and Ki-67 protein of 29 cases of VM was respectively 3% and (0.03 +/- 0.19)%. The expressive rate of iNOS and Ki-67 protein of HM was significantly higher than that of VM (P = 0.001 and 0). The expressive rate of Ki-67 protein of HM of proliferative phase was (12.67 +/- 7.65)% , which was significantly higher than that of HM of extinctive phase, (7.27 +/- 7.49)% (P = 0.028).</p><p><b>CONCLUSIONS</b>Expression of iNOS and Ki-67 protein of HM is significantly higher than that of VM, and the proliferative potency of HM is significantly higher than that of VM.</p>