Splenic auto infarction is seen in

Sickle cell disease As the largest unit of the mononuclear phagocyte system, the spleen is involved in all systemic inflammations, generalized hematopoietic disorders, and many metabolic disturbances. In each, the spleen undergoes enlargement (splenomegaly), which is the major manifestation of disorders of this organ. It is rarely the primary site of disease. Splenic insufficiency due to splenectomy or autoinfarction (as in sickle-cell disease) has one major clinical manifestation, an increased susceptibility to sepsis cause by encapsulated bacteria such as pneumococcus, meningococcus, and Haemophilus influenzae. The loss of filtering and antibody production functions both contribute to the increased risk of sepsis, which may be fatal. All asplenic individuals should be vaccinated against these agents to reduce the risk of this tragic complication.