Two reports of acute neonatal acalculous cholecystitis (necrotizing cholecystitis) in a 2-week-old premature infant and a term neonate.

We present 2 cases of acute acalculous cholecystitis, an extremely rare entity in newborns. A number of risk factors have been identified, such as inspissated bile, prematurity, sepsis, dehydration, total parenteral nutrition, medications, and Escherichia coli lipopolysaccharide endotoxin. In our cases, gallbladder bile had positive bacterial cultures for E coli. We present the cases of a premature infant and a term neonate who developed acute acalculous cholecystitis: one with several risk factors and the second with a very atypical presentation.