The spleen is enlarged in a variety of conditions such as malaria, glandular fever and most commonly in "cancers" of the lymphaticss such as lymphomas or the leukaemia.
It is removed under the following circumstances:
In general, spleens are removed by laparoscopy (minimal access surgery) when the spleen is not too large and when the procedure is elective. It is performed by open surgery for trauma or large spleens.
Prior to removal of the spleen if possible the patient should be vaccinated against certain bacteria. Failure to do so puts the patient post splenectomy to a condition called OPSI (overwhelming post splenectomy infection). These bacteria often cause a sore throat under normal circumstances but after splenectomy the infection becomes more severe.
Following splenectomy, the platelet count may rise to high levels in blood leading to an increased risk of clot formation.