Hereditary Pyropoikilocytosis

Hereditary pyropoikilocytosis (HPP) is a congenital red cell membrane disorder inherited in an autosomal recessive fashion. There is enhanced RBC fragmentation in vivo on heating; this occurs at a lower temperature compared with normal RBCs. Patients often have a severe haemolytic anaemia which is worse in the neonatal period.

Blood film features:

• Gross anisopoikilocytosis
• Bizzare poikilocytes with bud-like projections
• Microspherocytes

Differential diagnosis:

• HbH disease (lacks microspherocytes and bud-like projections from cells)
• Hereditary elliptocytosis
• Accidental warming of specimen tube

Other resources:

• ASH Image Bank: HPP