Merkel cell carcinoma in a kidney transplant patient: Case report and update on management.

Background: Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine tumor. Its incidence is markedly greater in immunocompromised patients. MCC is found almost exclusively on sun-exposed facial sites.

[Systemic sclerosis and scleroderma circumscripta--disturbances of selected serum parameters which are responsible for vascular changes and CD34 expression in involved skin].

Scleroderma is a connective tissue disease characterized by fibrosis confined only to skin (scleroderma circumscripta, morphea) or to skin and internal organs (systemic sclerosis, SSc) as a result of vascular changes, immune dysfunction and increased production of collagen and other extracellular matrix (ECM) components. Both types of scleroderma present clinical and histological similarities in skin changes but their pathogenic relationship is still not elucited. The aim of our study was to evaluate vascular changes in both types of scleroderma on the basis of: serum levels of gelatinases--MMP-2 and MMP-9, vascular endothelial growth factor (VEGF) and its soluble receptor 2 (sVEGFR2) and expression of CD34 antigen in skin changed samples.