Mineralization of collagen and elastic fibers in superficial dystrophic cutaneous calcification: an ultrastructural study.

The ultrastructural morphology of localized skin calcifications without associated diseases and with normal serum calcium and phosphate ion values is still unknown. In a case of superficial dystrophic calcinosis cutis (DCC), the role of collagen, elastin and ground substance in the process of calcification and the organization of the apatite crystals could be studied by light and electron microscopy despite technical difficulties in sectioning the hard tissue. Ultrastructural investigation revealed the nucleation of calcification being related to collagen and elastic fibers. No intracellular calcification was found. A flower-like arrangement of pleomorphic crystals was found around single collagen fibrils resembling the calcification of collagen seen in bone tissue. The elastic fibers showed a different pattern of calcification compared with other diseases (e.g. pseudoxanthoma elasticum) with known calcification of the elastic fibers. The process of mineralization was initially linked to the microfibrils of the elastic fiber.