Cardiovascular syphilis, light micrograph. The media of the aorta contains numerous thin walled blood vessels (white spaces containing red blood cells) surrounded by cellular infiltrate made up almost exclusively of plasma cells. Syphilis infects the ascending aorta causing aortic dilation and regurgitation. Contraction of the tunica intima leads to a tree bark appearance that is wrinkly (top right). Magnification: x120 when printed at 10 centimetres wide,