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Korean J Pancreas Biliary Tract. 2019;24(1):31-34

Publication date (electronic) : 2019 January 31

doi : https://doi.org/10.15279/kpba.2019.24.1.31

Hwaseong Ryu¹, Tae Un Kim^,1, Jin Hyeok Kim¹, Jieun Roh¹, Jeong A Yeom¹, Hee Seok Jeong¹, Je-Ho Ryu², Hyeong Seok Nam³

¹Department of Radiology, Pusan National University Yangsan Hospital, Yangsan, Korea

²Division of Hepato-Biliary-Pancreatic Surgery and Transplantation, Department of Surgery, Pusan National University Yangsan Hospital, Yangsan, Korea

³Division of Gastroenterology, Department of Internal Medicine, Pusan National University Yangsan Hospital, Yangsan, Korea

류화성¹, 김태언^,1, 김진혁¹, 노지은¹, 염정아¹, 정희석¹, 류제호², 남형석³

¹양산부산대학교병원 영상의학과

²양산부산대학교병원 간담췌/이식외과

³양산부산대학교병원 소화기내과

Corresponding author : Tae Un Kim Department of Radiology, Pusan National University Yangsan Hospital, 20 Geumo-ro, Mulgum-eup, Yangsan 50612, Korea Tel. +82-55-360-1840 Fax. +82-55-360-1848 E-mail; kimtaeun78@hanmail.net

Received 2018 January 8; Revised 2018 October 1; Accepted 2018 October 6.

Abstract

Trans Abstract

INTRODUCTION

Choledochal cysts are uncommon disease, which are defined as cystic dilatation of any portion of the bile ducts. The Todani classification based on the cholangiographic morphology, location, and number of intrahepatic and extrahepatic bile duct cysts is the most widely accepted. Type I cysts involve only extrahepatic biliary system and are the most frequent type. They are subdivided into IA (involve the entire extrahepatic bile duct), IB (segmental involvement of the extrahepatic bile duct), and IC (diffuse, fusiform, or cylindrical involvement of the extrahepatic bile duct with anomalous pancreaticobiliary ductal union). Type II cysts are true diverticula of the extrahepatic duct, usually occurring in the common bile duct. Type III cysts, also known as choledochoceles, are in the extrahepatic bile duct within the duodenal wall. Type IV cysts include type IVA (multiple extra and intrahepatic cysts), and IVB (multiple extrahepatic cysts). Type V cysts only involve the intrahepatic bile duct [1-4]. Unlike these choledochal cysts, hepatic duct diverticula are true diverticula arising from hepatic duct and they does not fit into the Todani classification system. In this report, we present a case of unusual diverticulum arising from left hepatic duct with sludge ball.

CASE

A 57-year-old woman presented with recent epigastric discomfort for one month. She had no specific past or family history. At presentation, there was no abnormal finding in the blood tests except mild increase of aspartate aminotransferase (136 IU/L), alanine aminotransferase (37 IU/L), alkaline phosphatase (136 IU/L). Abdominal computed tomography (CT) images revealed a 2.0 cm thin-walled cystic lesion containing non-enhancing high attenuation area in the porta hepatis (Fig. 1). Both intrahepatic bile ducts (IHDs) and common bile duct (CBD) were not dilated. Despite one month of conservative treatment, her intermittent abdominal pain was persisted. For further evaluation, magnetic resonance cholangiopancreatography (MRCP) was performed. MRCP showed diverticulum-like cystic lesion with sludge ball near the confluence portion of both IHD, but the exact origin of the lesion could not be identified. There was no anomalous pancreaticobiliary ductal union (APBDU) (Fig. 2). The initial impression was Todani’s type II cyst with sludge ball or hemorrhagic hepatic cyst. Surgical excision was performed because of her recurrent abdominal pain. At laparotomy, a 2.2 cm diverticulum containing biliary sludge arising from the extrahepatic portion of the left hepatic duct was found (Fig. 3). Subsequently, excision of diverticulum, and cholecystectomy were performed. Intraoperative cholangiography showed no APBDU, nor bile leakage. Histopathologic examination confirmed the presence of biliary epithelium lining the cystic lesion, which finding is consistent with biliary diverticulum (Fig. 4). But no inflammatory cell infiltration was observed on the specimen. The patient was discharged on 8th postoperative day without any postoperative complication and no further symptoms since the operation.

Fig. 1.

Contrast enhanced axial abdominal computed tomography images show a round cystic lesion (arrow) containing non-enhancing higher attenuation area in the porta hepatis.

Fig. 2.

Magnetic resonance cholangiopancreatography images demonstrate round cystic lesion with sludge ball near the confluence portion of both IHD. There is no anomalous pancreaticobiliary ductal union. IHD, intrahepatic bile duct.

Fig. 3.

On laparotomy, a 2.2 cm diverticulum containing biliary sludge arising from the extrahepatic portion of the left hepatic duct was found.

Fig. 4.

Histopathology of the resected specimen showed cystic lesion lined with biliary epithelium lacking of muscle layer (H&E, x200).

DISCUSSION

Hepatic duct diverticulum is considered to be very rare developmental anomaly [5]. Although the exact etiology is not well known, some reports have proposed that hepatic diverticulum may be incompletely developed shunt from proximal hepatic duct to the CBD below the cystic duct [6,7]. Given this etiological theory, diverticulitis caused by bile flow shunt and stasis may result in abdominal pain [8]. Kaneyama et al. [9] reported one patient with right hepatic duct diverticulum. Their patient had recurrent right upper abdominal pain, and histopathologic examination showed inflamed biliary diverticulum. This supports the hypothesis that local inflammation of hepatic diverticulum can be a cause of abdominal pain. But according to one autopsy study, similar hepatic duct anomalies can be found in 8% of individuals, suggesting most cases are asymptomatic [10]. In our case, no definite inflammatory change of hepatic diverticulum was detected on histopathology but symptom of patient was improved after surgical excision.

Only a few cases of hepatic duct diverticulum have been reported to date (Table 1). All patients were women with various ages, and presented with abdominal or back pain except for one infant patient. And most patients had right hepatic duct diverticulum. Only one case of left hepatic diverticulum was reported, but it had two separate stalks arising from LHD and CHD, which was different from our case. None of the previously published cases described ABPDU [8,9,11,12].

Table 1.

Previous reports of hepatic duct diverticulum

Various imaging modalities for preoperative evaluation of choledochal cyst are now available, such as CT, MRCP, ultrasonography, hepatobiliary scan, percutaneous transhepatic cholangiography, and endoscopic retrograde cholangiopancreatography (ERCP) [13]. Hepatic duct diverticula can be confused with other cystic lesions such as hepatic cysts, enteric duplication cysts, hepatic artery aneurysm, and duplication anomalies of gall bladder [14]. Preoperative MRCP and ERCP can be helpful in diagnosis of bile duct diverticulum, and establishment of surgical plan [8]. Hashimoto et al. [5] reported that ERCP is the most effective for diagnosis of bile duct diverticulum. But in cases with uncertain preoperative diagnosis, intraoperative cholangiography is needed.

There is no established treatment for hepatic duct diverticulum. Reviewing published case reports, all cases were treated with surgical excision, and no further symptoms were reported (Table 1). Total excision of diverticulum would be good treatment option in symptomatic patients who can justify morbidity expected from surgical intervention [12].

In conclusion, we reported an unusual left hepatic diverticulum not included current Todani’s classification. Because of its rarity, little is known about hepatic duct diverticulum. Further studies are required to establish new classification, and to select ideal diagnostic modality, and treatment of hepatic diverticulum.

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