Calciphylaxis and metastatic calcification associated with nephrogenic fibrosing dermopathy

Background: Calciphylaxis and metastatic calcification are known complications of chronic renal failure. Recently, a sclerosing condition of the skin termed nephrogenic fibrosing dermopathy (NFD) has been described in patients with renal disease, many of whom have undergone hemodialysis and/or renal transplantation. To our knowledge, the simultaneous occurrence of both conditions in the same patient, in the same lesion, has not been previously reported. Case report: We report the clinical, microscopic, and immunohistochemical features of two patients with chronic renal failure whose lesional skin biopsies showed both subcutaneous calcification and NFD. We consider the possible mechanisms that might explain the coexistence of these two disorders. Results: Both patients presented with erythematous, indurated skin over the lower extremities. Purpuric, reticulated patches, necrosis, or ulceration were not observed. Microscopic examination showed the characteristic changes of NFD involving dermis and subcutaneous septa. In addition, biopsies of both individuals showed subcutaneous calcification, one in a diffuse distribution and the other involving the walls of subcutaneous vessels, as seen in calciphylaxis. Calcification was not suspected clinically in either case. Conclusions: Metastatic calcification or calciphylaxis and NFD can occur simultaneously in patients with chronic renal failure and may be found together in the same lesion. Because subcutaneous calcification may not be suspected clinically in these cases, and in view of the adverse outcomes frequently associated with calciphylaxis, we recommend deep incisional biopsy of patients presenting with the clinical features of NFD. Both the fibrosis and the calcification of chronic renal failure may be related to the activity of transforming growth factor-beta/Smad signaling cascades.