Necrotic skin lesions in a dialysis patient: a multifactorial entity.

A female dialysis patient with a consistently high serum calcium phosphate product presented with large necrotic skin lesions with ulcers. The clinical course was highly suggestive of calciphylaxis. Parathyroidectomy was followed by the healing of the lesions. New skin lesions appeared following relapse of hyperparathyroidism. Her clinical records included a long past of hypertension, which was the cause of her renal failure. She had a limited walking range and previously had presented bilateral ulcers of vascular origin. This case presents a type of lesion which bears a serious prognosis in dialysis patients. The clinical context and the presentation of the lesions are compatible with multiple etiology: vascular lesions and calciphylaxis. The documented longitudinal follow-up illustrates the importance of treating the different factors known to participate in the appearance of skin lesions in dialysis patients. Particularly, it stresses the benefit of performing parathyroidectomy, even if the parathyroid hormone level is not in the range normally accepted as requiring surgical removal of parathyroid glands.

MDM-2 protein is expressed in different layers of normal human skin.

MDM-2 is one of the target genes of the p53 tumor suppressor protein. Its best characterized function is found in the inhibition of p53's ability to modulate transcription. Deregulated expression of MDM-2 could thus at least partially substitute for p53 mutation in the process of tumorigenesis. We show here that MDM-2 is highly expressed in biopsies of normal human skin or in vitro reconstituted human skin. The protein is detected in the nucleus of keratinocytes throughout the different layers of the epidermis and in reconstituted skin as early as the two to three cell layer stage. The 90 kiloDalton (kD) protein is one of the major forms detected in Western blot experiments. MDM-2 is detected in skin reconstituted from keratinocytes in which p53 is inactivated by mutation or degradation by E6 protein, providing evidence that MDM-2 expression in the skin can occur in the absence of wild type p53. Moreover, we found no correlation between the p53 status and MDM-2 expression levels in a series of basal and squamous cell carcinomas or Bowen diseases. Our data provide first evidence for the expression of MDM-2 in a differentiated adult tissue.