Riedel's Lobe of the Liver

Riedel's lobe of the liver is an inferior, tonguelike projection of the anterior border of the right lobe of the liver to the right of the gallbladder inferior to the costal margin. Clinically, this may be confused for a mass, prompting imaging referral. Recognition of this normal variant, can therefore be reassuring to the referring clinician. Riedel's lobe can also pose a challenge during right-sided laparoscopic procedures, and a case of gastric outlet obstruction due to a Riedel's lobe has been reported.

The etiology of Riedel's lobe has been debated. It has been attributed to edema from cholecystitis and appendicitis, hepatic tumors, and constriction from tight corsets (it is more common in women). More recent work has shown that its prevalence increases with age, being seen on imaging in about 60% of people between 45 and 65 years of age, and 25% of people between 20 and 45 years of age. The observation that the craniocaudal extent of the liver actually diminishes with age, while the prevalence of Riedel's lobe increases with age has led some to suggest that Reidel's lobe is the result of skeletal degenerative changes.

References

• Akbulut S, Cakabay B, Sevinc MM, Basak F. Gastric outlet obstruction caused by Riedel's lobe of the liver: a diagnostic and therapeutic challenge for surgeons. Hepatogastroenterology. 2011 Mar-Apr;58(106):589-92.
• Chien GW, Orvieto MA, Galocy RM, Sokoloff MH, Shahav AL. Technical considerations for laparoscopic right renal surgery in presence of Riedel's lobe of the liver. J Endourol. 2005 Apr;19(3):300-2.
• Gillard JH, Patel MC, Abrahams PH, Dixon AK. Riedel's lobe of the liver: fact or fiction? Clin Anat. 1998;11(1):47-9.