Pictorial review CT findings in congenital anomalies of the spleen

There is a wide range of congenital anomalies of the spleen. Some are common, such as splenic lobulation and accessory spleen. Other less common conditions, such as wandering spleen and polysplenia, have particular clinical significance. Radiologists need to be aware of the various congenital variants of the spleen in order to recognize clinically important anomalies and to avoid mistaking less significant ones for an abnormality. In this pictorial review, the embryology of congenital anomalies of the spleen as well as their appearance on CT are described, diagnostic pitfalls are identified and complications of the anomalies are discussed. The spleen is included and well demonstrated on every CT of the abdomen. It is also often included on CT of the lower part of the chest. There is a wide spectrum of congenital anomalies, ranging from the common splenic lobulation and acces- sory spleen to rare conditions such as a wandering spleen and polysplenia. The majority of these anatomical variants have no clinical significance, although they need to be recognized as anatomi- cal variants by the radiologist. On the other hand, a wandering spleen may rotate around its pedicle and present as an acute abdomen due to splenic infarction. Awareness of the various splenic congenital variants is important for the radi- ologist to interpret the findings correctly and to avoid mistaking them for an abnormality. We review the embryology of congenital anomalies of the spleen as well as their appear- ance on CT, stress pitfalls and describe complica- tions resulting from these anomalies.