We report two patients with renal failure who developed painful symmet
rical ulceration over the proximal thighs and abdominal wall. Histolog
ical examination of the ulcerated areas revealed intravascular calcifi
cation. This phenomenon has been termed calciphylaxis and is a rare co
mplication of renal failure. The pathogenesis is poorly understood, Ho
wever, abnormalities of calcium/phosphate metabolism and of coagulatio
n are important.