Congenital wandering spleen is a very rare birth defect in which the ligaments that hold the spleen in its usual position in the upper left abdomen (splenic peritoneal attachments) are missing or underdeveloped. Congenital wandering spleen has been observed in children from 3 months to 10 years old; the disorder is. most commonly found in children who are younger than 1 year old. Wandering spleen is also sometimes called displaced spleen, drifting spleen, floating spleen, splenic ptosis, splenoptosis, or systopic spleen. Wandering spleen is extremely rare, with approximately 50 recorded cases in children under 10 years of age.