Anomalies and Anatomic Variations of the Spleen

The spleen develops within the dorsal mesogastrium and rotates to the left, becoming fixed in the left subphrenic location by peritoneal reflections, and it usually develops as one fused mass of tissue. There is a wide spectrum of congenital anomalies and anatomic variations of the spleen, ranging from common conditions such as splenic lobulation and accessory spleen to rare conditions such as wandering spleen and asplenia/polysplenia.