Marfan syndrome: demonstration of abnormal elastic fibers in skin

The back skin of a 15-year-old girl with Marfan syndrome has been investigated using scanning (SEM) and transmission (TEM) electron microscopy. The SEM showed that admixed with normal-looking portions, there were abnormal portions of the elastic fibers which were composed of many unusual fine fibers (5-22 nm in diameter), and had a cobweb-like appearance. The TEM showed that these fine fibers were substructures of the amorphous material and were surrounded by microfibrils. It is suggested that the fine fibers could be abnormal elastic fibers resulting from the incomplete fusion of the elastic units.