[The pathological characteristics and clinical significances of maturational change of port-wine stain].

Objective In this study histologic observations were presented to elucidate the possible mechanism of maturational change of port-wine stain( PWS). Methods Normal PWS(3 cases) , thicken PWS (11 cases) and nodular PWS (9 cases) were included to present histologic observations. Results Normal PWS, only shows mild dilated, thin-walled vessels within superficial derm is. Thicken PWS, shows further dilated vessels and sebaceous gland throughout dermis and superficial subcutaneous fat. Nodular PWS can be divided into three groups. Ⅰ Similar to thicken PWS, shows further dilated vessels and sebaceous gland throughout dermis and superficial subcutaneous fat. Ⅱ Shows Large number of dilated vessels, honeycombin and less vascular mesenchymall. Ⅲ Tenacious texture shows mild dilated vessels, diffused collagen, mesenchymal rarefactin, lymphocyte infiltration and lymphedema change. Conclusions Histologic examination revealed not only the expected vascular abnormalities, but also a number of widely distributed hamartomatous changes in thicken and nodular PWS. The complex hamartomatous changes suggest a genetically determined, multilineage developmental field defect in the pathogenesis of PWS. Key words: Port-wine stain;  Enlargement mechanism;  Hamartomatous changes