海绵状血管瘤(cavernous hemangioma)又称静脉畸形(venous malformation):臀部肿物,表面鲜红色分叶状,深部紫蓝色,边界不清,柔软而有弹性,压之状似海绵鲜红斑痣(nevus flammeus)又称毛细