Incremental Value of Live/Real-Time Three-Dimensional Transesophageal Echocardiography Over the Two-Dimensional Technique in the Identification of Accessory Liver Lobe Presenting as a Right Atrial Mass

Abstract

AN ACCESSORY LIVER LOBE is a congenital abnormality of hepatic tissue overgrowth. It is related to embryonic heteroplasia or rarely may occur secondary to trauma or surgery. 1 Wang C Cheng L Zhang Z et al. Accessory lobes of the liver: A report of 3 cases and review of the literature. Intractable Rare Dis Res. 2012; 1: 86-91 PubMed Google Scholar When in direct continuity with the liver, it is termed a “supernumerary liver lobe”, and when completely separate from the liver, it is described as an “ectopic liver lobe”. 2 Glenisson M Salloum C Lim C et al. Accessory liver lobes: Anatomical description and clinical implications. J Visc Surg. 2014; 151: 451-455 Crossref PubMed Scopus (30) Google Scholar The reported incidence of accessory liver lobes, including Riedel’s lobe, which is the most well-known type seen as a tongue-like protrusion of hepatic segments V and VI, variably is stated as being 3.3%-to-31% in the general population. 3 Sham R Sain A Silver L. Hypertrophic Riedel's lobe of the liver. Clin Nucl Med. 1978; 3: 79-81 Crossref PubMed Scopus (14) Google Scholar ,4 Gillard JH Patel MC Abrahams PH et al. Riedel's lobe of the liver: Fact or fiction?. Clin Anat. 1998; 11: 47-49 Crossref PubMed Scopus (25) Google Scholar An accessory liver lobe can be found at many sites, such as the gallbladder, spleen, retroperitoneum, pancreas, adrenal gland, portal vein, diaphragm, thorax, gastric serosa, inferior vena cava (IVC), testes, and umbilical vein. An accessory liver lobe presenting as a right atrial (RA) mass is a very rare occurrence, and there are only 16 cases reported in the literature. Ansari-Gilani et al, in their case report of a supernumerary liver lobe, have commented on the echotexture of the RA mass being similar to liver tissue on two-dimensional transesophageal echocardiography (2D TEE), but in the remainder 15 cases, echotexture was not reported. Also, three-dimensional transesophageal echocardiography (3D TEE) was not performed in any case. The authors report a case of a supernumerary liver lobe that extended from the intrahepatic IVC into the RA and the utility of live/real-time3D TEE in making a more confident definitive diagnosis of this lesion. To the best of the authors’ knowledge, this has not been previously reported.