Two cases of linear focal elastosis: different histopathologic findings

Case 1 A 16-year-old Korean man presented with asymptomatic erythematous st riae-like bands on his back which had been present for 6 months and had mig rated to his shoulder (Fig. 1a). He had no history of corticosteroid therap y, rapid gain or loss of weight, debilitating infection or illness. Histopa thologically, fine, fragmented elastic fibers were shown in the dermis, but there were no clumped elastic fibers (Fig. 2a). Electron microscopy showed an irregular, fragmented, electron-dense granular substance and a fragment ed, electron-lucent substance between the normal collagen fibers, and no mi crofibrils (Fig. 3a). This indicates the degeneration of elastic fibers. Case 2 An 18-year-old Korean man presented with asymptomatic yellowish stri ae in the lumbar area which had been present for 2 years (Fig. 1b). He had no specific medical history. Massive, well-demarcated basophilic fibers wer e observed in the dermis with light microscopy. These fibers were stained p ositively with elastic stain (Fig. 2b). Electron microscopy showed a fragme nted, electron-dense granular substance and numerous microfibrils near the substance (Fig. 3b), which suggests active elastogenesis.