Angioma serpiginosum.

Seven cases of angioma serpiginosum were examined in our clinic during a period of 15 years. A histological study performed in six of them revealed an increased number of ectatic capillaries in the dermal papillae. One of the cases, a 31-year-old woman, was studied by electron microscopy. The dilated capillaries consisted of endothelial cells, pericytes and veil cells. Walls of capillaries showed a heavy precipitation of fine fibrillar material admixed with collagen fibers. Most vessel walls were composed of two layers. The inner layer consisted of fine fibrillar material and the outer layer consisted of bundles of collagen fibers of about 40 nm in diameter. Characteristic findings in the endothelial cells were the formation of accessory lumen or slit-like protrusion of lumen into the endothelial lining. It appears that angioma serpiginosum is not a simple telangiectasia of preexisting vessels but represents a type of capillary nevus, which has a tendency to manifest itself in the form of capillary dilation and proliferation.