Infantile pyknocytosis: an under-recognized form of neonatal hemolytic anemia?

Infantile pyknocytosis (IP) is an under-recognized hematological entity of newborns that can cause a severe neonatal hemolytic anemia. A careful, prompt, and accurate peripheral blood smear examination is essential to establish the diagnosis. Here we describe the clinical features and histological parameters of 1 case of IP. Spontaneous resolution usually occurs by 4 to 6 months, but red blood cell transfusion may be needed if the anemia is severe.