Cortical necrosis is a rare form of kidney tissue death that affects only part or all of the outer layer (cortex) of the kidney and not the inner layer (medulla). Renal cortical necrosis can occur at any age. About 10% of cases occur in infants and children. More than half of newborns with cortical necrosis are delivered with abrupt placental separation (placental abruption); the other most common cause is bacterial infection of the bloodstream (sepsis). In children, cortical necrosis can be followed by infection, dehydration, shock, or hemolytic uremic syndrome. In adults, bacterial sepsis causes cortical necrosis in about 1/3 of all cases. Causes of renal cortical necrosis Renal cortical necrosis: a rare form of arterial infarction. It is characterized by necrosis of cortical tissue followed by calcification. It is located precisely in the subperitoneal area, with no involvement in the proximal medullary area or in the medulla. Renal cortical necrosis can occur at any age. In women, complications of pregnancy (e.g. placental abruption, placenta praevia, uterine bleeding, puerperal sepsis, amniotic fluid embolism, intrauterine death, pre-eclampsia) account for more than 50% of cases, while bacterial sepsis accounts for 30%. Other causes include hemolytic-uremic syndrome, super-acute rejection of transplanted kidneys, burns, pancreatitis, snake bites, and poisoning (e.g., phosphorus, arsenic). About 10% of cases occur in infancy and childhood. In neonates, more than 50% of cases are caused by placental abruption, and the next common cause is bacterial sepsis. In children, infection, extracellular volume loss, shock, and hemolytic-uremic syndrome are common causes. Suspected mechanisms include vasospasm, activation of coagulation mechanisms, endotoxin, immunologic injury and direct endothelial cell damage. The damage is extremely similar to the general Shwartzman phenomenon in animal studies. Renal cortical necrosis is the result of obstruction of small arteries in the renal cortex due to various diseases. Other causes include rejection of the transplanted kidney, burns, inflammation of the pancreas (pancreatitis), injuries, snake bites and poisoning, such as phosphorus and arsenic poisoning.