Riedel's lobe

(Bernhard Moritz Carl Ludwig Riedel, 1846 - 1916, German surgeon), downward tongue-like projection of the anterior edge of the right liver lobe to the right of the gallbladder, seen most frequently in women. It has been considered as either a sessile accessory lobe of the liver or as a normal variant. A Riedel lobe varies in size and shape and may extend into the right iliac fossa. Commonly these persons present with a narrow chest. Riedels lobe may occasionally be attached to the liver by a wide sulcus, which can undergo torsion, but in most persons this anomaly is of no clinical significance although it might erroneously be diagnosed as hepatomegaly.

The plain film of the abdomen shows a downward, tongue-like soft tissue structure extending from the lower border of the right lobe of the liver and displacing the air in the ascending colon to the median direction. On ultrasound the Riedel lobe can be visualized in the sagittal plane as a structure with the same echo pattern as the liver and projecting from the inferior border of the liver in front of the right kidney.

ALB