The term capillary malformation usually refers to the port wine stain but may apply to the nevus simplex.
The port wine stain may occur as an isolated finding. If involving the forehead, consider the Sturge Weber Syndrome (PWS of the forehead with CNS and ocular abnormalities). When familial, it may be part of Capillary Malformation with AVMS. If over a limb with hypertrophy, think Klippel Trenaunay Syndrome. They may be paired with pigmentary congenital lesions in Phacomatosis Pigmentovascularis. The combination of spinal arteriovenous malformation and a vascular skin lesion, e.g. port wine stain, affecting the corresponding dermatome is called the Cobb's Syndrome.
PWS of the arm and hand.
Sturge Weber Syndrome.
Klippel Trenaunay Syndrome The triad of a port wine stain, underlying hypertrophy of soft tissue and/or bone and venous varicosities.
Phacomatosis Pigmentovascularis Bilateral Nevus flameus and aberrant Mongolian spots on the back. J Dermatol Venereol Leprol. 2010 May-Jun;76(3):307
Cobb's Syndrome The combination of spinal arteriovenous malformation and a vascular skin lesion, e.g. port wine stain, affecting the corresponding dermatome. For a picture, see Trans Am Ophthalmol Soc. 2013 Sep; 111: 180–215
Capillary Malformation with AVMS
Multifocal Lymphangioendothelioma with Thrombocytopenia The skin shows hundreds of congenital red-brown skin plaques as large as a few centimeters.
Acquired port wine stain
Benign Lymphangioendothelioma A solitary, slowly-enlarging, erythematous to brown macule and/or plaque in an adolescent or young adult is characteristic of benign lymphangioendothelioma, also known as acquired progressive lymphangioma.