The fetal spleen is lobulated, and these lobules normally disappear before the birth. Lobulation of the spleen may persist into adult life and be typically seen along the medial part of the spleen. A persisting lobule results in a variation in shape of the spleen.
Comment:
Sometimes a splenic lobule may extend medially anterior to the upper pole of the left kidney and less often posterior to the upper pole of the left kidney. Although these lobules are not of any clinical importance, close relation of the splenic lobule to the upper pole of the left kidney may cause misinterpretations as a mass originating from the kidney by the radiologists.