Clinicopathological Findings And Expression Of WT1 And CD31 In Non-involuting Congenital Hemangioma

ObjectiveIn this research,we analyze the clinicopathological features of the Non-involuting congenital hemangioma of 38 cases,and we also assessed expression of WT1,CD31 in Non-involuting congenital hemangiomas by imunohistochemical staining.Additionally,we examined possible correlations between WT1 and CD31.Methods(1)A total of 38 cases of children's Non-involuting congenital hemangioma that were collected from January 2014 to May 2016 from Department of Pathology,Children's Hospital,Zhejiang University School of Medicine.All specimens were rechecked by two senior pathologists.(2)On the basis of clinical manifestations,the lesions could be divided into two groups:bossed group and plaque-like group.Analying the clinical data,and comparative analying the tumor's pathological character using routine HE and Masson staining.(3)The tumors labeled with WT1 and CD31,The SPSS22.0 were used to test the expression difference and correlation between WT1 and CD31 in the different clinical phenotype of NICH.Results(1)Of the 38 cases studied,including 27 males and 11 females,Patients' age ranges from 1Y6M to 10Y3M,the mean age was 4Y10M.7 cases were located in the head and neck region,13 cases in the trunk,and 8 cases in the upper limbs,10 cases in the lower limbs.All lesions were solitary.According to clinical phenotype,it could be divided into two groups:(1)bossed group:27 cases,all were slightly or obviously bossed,6 cases with normal overlying skin,the remains were pink,blue-red or purple.(2)plaque-like group:11 cases,the masses were located in the subcutaneous with coarse skin.The volume of the tumors was unequal,ranging from 0.5×1×1cm3 to7.5x4x3.5 cm.The tumors were dominated by lobules of capillaries,the lobules was variables in size and shape.The small intralobular vessels were lined by endothelial cells.Through further examine,we found:(1)bossed group:15 cases with hobnailed nuclei,21 cases with thromboses,3cases with hemosiderosis,11 cases with lymphatics around the lobules,1 case with focal calcification and 15 cases with adipose tissues grow into lobules arround cutting edge and superficial dermis were observed.3 cases with pieces of adipose tissues hyperplasia,and the entire lobules were present "spider web" structure.Masson staining showed collagen fiber hyperplasia in the small vessel walls.(2)plaque-like group:the lobules appeared more cellular than thoses of bossed mass,include endothelial cells and pericyte.11 cases with hobnailed nuclei,5 cases with pieces of lymphatics around the lobules,3 cases with thromboses.No collagen fiber hyperplasia under Masson staining.(2)Immunohistochemical study showed WT1 in Non-involuting were cytoplasmic staining,it was positive in the endothelial cells and pericytes,with a clear demarcation between other tissues.The abnormal vessels in the fibrous tissues between the lobules was negative for WT1,the rate of positive of WT1 had statistical significance among Non-involuting congenital hemangioma and the vascular malformation(Fisher exact probability test,P value<0.01).The expression intensity of WT1 in the plaque-like group had statistical significance compared with the bossed group(Personx2 =10.481,P value<0.05).CD31 was intensely and difusely expressed in all cases of Non-involuting congenital hemangioma,including the small vessels of the lobules,irregular stellate vessels and the anomalous vessels in the fibrous tissues between the lobules.CD31 also expressed within microvessels in the surrounding normal skin tissues.CD31 appeared positive in vascular malformation,the rate of positive had no statistical significance among them(Fisher exact probability test,P value>0.05).The expression intensity of CD31 in the plaque-like group had statistical significance compared with the bossed group(Personx2=10.596,P value<0.05).The expression of WT1 have positive correlation with CD31 in Non-involuting congenital hemangioma(Person correlation test,r=0.384,P<0.05).Conclusion(1)In the two clinical phenotype,bossed type is more common,and the masses were more obviously in enlargement.There were some difference between bossed group and plaque-like group:the bossed group was decreased in the number of tumor cells,endothelial cells with hobnailed nuclei were more notable,collagen fiber hyperplasia were observed in the walls of the small vessels,and the basement membranes were thickened,the lumens were dilated,adipose tissues hyperplasia instead of the tumor tissues,present the imagine of slowly and partially involution,and the involuting progressed from subcutaneous,cutting edge to the center of the mass.The plaque-like Non-involuting congenital hemangioma appeared more cellular than thoses of bossed mass,including endothelial cells and pericytes.There were no reducing of endothelial cells with hobnailed nuclei,no adipose tissues hyperplasia,and no collagen fiber hyperplasia,present the imagine of non-involuting.Surgical excise was the first choice,relapse-free and with good prognosis.(2)WT1 were positive in all Non-involuting congenital hemangioma specimens,WT1 has positive correlation with CD31.They may regulated the development of the Non-involuting congenital hemangioma together,and the machanism needs to be further study.