Hereditary pyropoikilocytosis: a rare but potentially severe form of congenital hemolytic anemia.

Hereditary pyropoikilocytosis is an inherited red cell membrane disorder with characteristic morphology: striking anisopoikilocytosis with red cell fragmentation and microspherocytes. Clinical and laboratory physicians must be aware of the potential impact of this disorder on accuracy of complete blood count results reported by automated hematology instruments. Recognition of the morphologic and laboratory findings are important for recognizing this potentially severe anemia.