[Hypertrophic port-wine stain: a clinicopathological analysis of 24 cases].

Objective: To investigate the clinical and pathologic features, diagnosis and differential diagnosis of hypertrophic port-wine stain (PWS). Methods: Cases of hypertrophic PWS, collected from Henan Provincial People's Hospital between 2012 and 2018, were retrospectively analyzed for their clinical and pathologic features, immunophenotype and histochemical data, and the relevant literature was reviewed. Results: Twenty-four cases of PWS were included in this cohort, located in the head and neck region (20 cases), limbs (2 cases), and trunk (2 cases). The clinical presentations were mainly red or purple-red plaques or slow growing, painless nodules, or thickened and raised above the skin surface. Microscopically, deformed blood vessels showed honeycomb-like, plexiform or cluster-like growth pattern, and diffusely involved the dermis, skin appendages, subcutaneous fat tissue, and deep skeletal muscles; The vascular lumen of the deformed vessels was dilated (≥100 µm in diameter), and in 18 cases the lumen was greater than 400 µm. The superficial dermis mainly contained few deformed capillaries. The deep wall showed thickening of blood vessel wall and fibrous tissue hyperplasia. Elastic fiber and Masson staining indicated abnormal venous vessel, which in some cases contained small amount of abnormal arterioid vessel,without vascular endothelial cell proliferation in all cases. In 24 cases, 19 cases had epidermal atrophy, 6 with vascular chronic inflammation or epidermal ulcer, 4 with capillary hemangioma, 4 with sebaceous gland hyperplasia, 2 with epidermal papillary hyperplasia and 2 with vascular keratomas. Conclusions: PWS is a common congenital capillary malformation. The number of histologically deformed capillaries is reduced and they usually locate in the superficial part. The deep vascular wall is increased with thick venous malformation, diffusely involving the dermis and deep skeletal muscle. Furthermore, PWS needs to be differentiated from infantile hemangioma, cavernous hemangioma and vascular keratomas.