Sorafenib-associated remission of psoriasis in hypernephroma: case report.

Psoriasis is a disease characterized by epidermal hyperproliferation that results in the formation of lesional plaques covered by scale. Psoriasis is thought to be angiogenesis dependent. Clear cell renal cell carcinoma is a hypervascularized solid tumor associated with loss of function of the von Hippel-Lindau (VHL) tumor suppressor gene and increased Raf-1 activity. A 68-year-old man who suffered from recalcitrant psoriasis for over 50 years was treated with sorafenib for metastatic clear cell renal carcinoma. One month later, his psoriasis, previously 8 x 6 cm on the mid posterior thorax, completely resolved. Sorafenib works by inhibiting several receptor tyrosine kinases (RTKs), such as vascular endothelial growth factor (VEGFR) and platelet-derived growth factor receptor (PDGFR)). It also inhibits intracellular Raf kinase (Raf-1), which targets the ubiquitous mitogen-activated protein kinase (MAPK) intracellular signal transduction pathway. We suggest that this patient's remission of psoriasis could be related to the inhibition/modulation of VEGF, PDGFR, Raf-1, and MAPK.