What is the most common cause of a small spleen?
- Sickle cell disease resulting in splenic autoinfarction is the most common cause of a small spleen. The spleen will typically have diffusely very high attenuation due to calcification, as well as diffusely very low signal intensity due to iron deposition from chronic blood transfusions.
- The other common causes of a small spleen (splenic hypoplasia) is asplenia or polysplenia syndrome. Asplenia is a condition where the spleen is absent or severely underdeveloped, while polysplenia is a condition where multiple small spleens are present. Both of these conditions are congenital, meaning they are present from birth.
- In asplenia syndrome, the spleen is either completely missing (asplenia) or greatly reduced in size (splenic agenesis). This condition is often associated with other congenital abnormalities of the heart and other organs. Asplenia can lead to an increased risk of certain infections, especially from encapsulated bacteria such as Streptococcus pneumoniae, Haemophilus influenzae type B, and Neisseria meningitidis. Due to the spleen’s role in filtering blood and helping the immune system respond to infections, individuals with asplenia are at higher risk of severe infections.
- In polysplenia syndrome, multiple small spleens are present, but they may not function properly or have a normal structure. Polysplenia can also be associated with other congenital malformations, particularly those affecting the heart and abdominal organs.
- Other less common causes of a small spleen include various genetic disorders and certain medical conditions that affect spleen development or cause splenic atrophy.
- If an individual has a small spleen or is suspected to have splenic hypoplasia, they should undergo a thorough evaluation by a healthcare professional, and further investigations may be necessary to identify any associated congenital anomalies or potential health risks related to splenic function. Management may involve close monitoring for infections and vaccination against certain bacteria to reduce the risk of serious complications.
