Hypersplenism and Hyposplenism

The spleen is a well-capsulated small vascular organ located in the upper quadrant of the abdomen measuring 11.0 × 5.0 × 7.0 cm and weighing 70–200 g in a normal adult. It contains both white pulp and red pulp. The white pulp is a secondary lymphoid organ which is composed predominantly of B cells and some T cells and functions similar to a lymph node. The red pulp filters 150 ml of blood per minute via an extensive sinusoidal system lined by macrophages which remove antibody-bound substances, bacteria, foreign material, and damaged red blood cells. The two major functions of the spleen are to store blood and eliminate aged or defective cells. It is also an important secondary immune organ. Disorders of the spleen can have a significant impact on the health of individuals affected by them, leading to anemia, thrombocytopenia, and increased risk of infections. The spleen has hematopoietic potential between the second and sixth months of fetal life, but this activity is abolished after bone marrow can perform this function. It is important to note that splenomegaly can be associated with either hypersplenism or hyposplenism. Many of the conditions that cause splenomegaly can cause a functional hyposplenism. Accordingly, the examination and differential are similar for both conditions.