ACQUIRED PERFORATING DERMATOSIS OF DIABETES-MELLITUS AND RENAL-FAILURE - FURTHER ULTRASTRUCTURAL CLUES TO ITS PATHOGENESIS

An ultrastructural study of a typical case of acquired perforating der matosis in a patient with renal failure and diabetes mellitus is repor ted. Crystal-like microdeposits of an electron-lucid material were det ected in the upper dermis, close to the transepidermal channel. Compac t macrophage conglomerations surrounded the deposits, and a strong his tiocytic response was present. Mononuclear inflammatory cells of ''act ivated'' type penetrated the acanthotic epidermis provoking basement m embrane dissolution and widening of interkeratinocyte spaces. Collagen fibers were seen in the keratotic plug, indicating the process of tra nsepidermal elimination. Our observation supports the hypothesis sugge sting that some kind of storage phenomenon may be at the origin of per forating skin lesions in renal failure patients.