[Erythropoietic protoporphyria. Ultrastructure of the basal pericapillary complex in the superficial dermis].

An ultrastructural investigation of erythropoietic protoporphyria reveals the high complexity of the basal complex that surrounds the superficial capillaries. There is a tremendous replication of the usual basement membrane, but in chips, with the constitution of an uneven network within an amorphous substance. Few collagen fibrils and microfibrils are present. Furthermore the architectural upheaval is characterized by the penetration of endothelial cell pseudopoda and of slender processes of perithelial cells. The basal complex is clearly encompassed by a layer of epithelial cells. The overall thickness reaches 5 micra.