Peroral video cholangioscopic findings in a biliary intraductal mucinous cystic neoplasm

Mucinous cystic neoplasm (MCN) of the liver is a biliary counterpart of pancreatic MCN, usually occurring in the liver, but occasionally extending to the extrahepatic bile duct [1] [2]. We present a case of MCN with extrahepatic bile duct extension diagnosed by peroral video cholangioscopy (POVCS).

A 49-year-old woman was admitted with a week of vomiting without abdominal pain, and jaundice. Abdominal ultrasound ([Fig. 1]), contrast-enhanced computed tomography ([Fig. 2]), and magnetic resonance cholangiopancreatography ([Fig. 3]) revealed a multilocular perihilar cystic lesion with dilation of B₂, B₃, and B₄. Endoscopic retrograde cholangiography showed an elliptical defect from the left hepatic duct to the perihilar bile duct ([Fig. 4]). Intraductal ultrasonography demonstrated multilocular, cyst-in-cyst structures in the extrahepatic bile duct ([Fig. 5]). Subsequent POVCS (CHF-B260; Olympus, Tokyo, Japan) revealed a mass filling the bile duct covered with smooth and translucent bile duct mucosa, suggesting a subepithelial growth without bile duct communication ([Fig. 6]; [Video 1]). A directly visualized biopsy showed no evidence of malignancy.

Fig. 1 Ultrasound images showing dilatation of B_2, B_3, B₄, and multilocular perihilar cystic lesions (arrows). PL, left portal vein; Bs, perihilar bile duct; GB, gallbladder; PV, portal vein.

Fig. 2 Contrast-enhanced computed tomography images showing multilocular perihilar cystic lesions (arrows) with dilatation of B₂, B₃, and B₄.

Fig. 3 Magnetic resonance cholangiopancreatography images showing multilocular perihilar cystic lesions (arrows) with dilatation of B₂, B₃, and B₄.

Fig. 4 Endoscopic retrograde cholangiography showing an elliptical defect from the left hepatic duct to the perihilar bile duct.

Fig. 5 Intraductal ultrasonography showing multilocular, cyst-in-cyst structures in the extrahepatic bile duct.

Fig. 6 Endoscopic image showing the smooth and hyperpermeable bile duct mucosa, suggesting intraductal growth.

Peroral video cholangioscopy (CHF-B260, Olympus, Tokyo, Japan) performed using a mother–baby system under fluoroscopic guidance.

We diagnosed intraductal MCN of the liver based on the findings of the imaging modalities. The patient underwent left lobectomy and caudate lobectomy. A cholangiogram of the resected specimen showed no biliary communication. Histologically, the dilated ducts were filled with a polypoid cystic mass consisting of lining columnar epithelium and ovarian-like stroma, features consistent with MCN with low grade dysplasia. The tumor was located beneath the lining epithelium of the left hepatic duct and there was no communication between the ductal lumen and cystic spaces. There was no evidence of recurrence at 3-year follow-up.

This is the first report of biliary intraductal MCN, suggesting an origin from Glisson’s capsule of the large hepatic bile duct. A recent report was the first to describe extrahepatic bile duct intraductal MCN using POVCS [3]. A cystic mass with smooth surface and compression due to distension without bile duct communication may be the characteristic findings of biliary intraductal MCN with POVCS.

Endoscopy_UCTN_Code_CCL_1AZ_2AC

Competing interests: None

Acknowledgments

We express our deepest appreciation to Dr. Taiki Kudo, Dr. Yoko Taya, Dr. Shuhei Kawahata (Department of Gastroenterology and Hepatology, Hokkaido University Hospital, Sapporo, Japan), Dr. Kazumichi Kawakubo (Department of Gastroenterology and Hepatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan), and Dr. Masaki Kuwatani (Division of Endoscopy, Hokkaido University Hospital, Sapporo, Japan) for clinical advice. We also thank Dr. Yuko Omori (Department of Pathology, Teine-Keijinkai Hospital, Sapporo, Japan) for skillful analysis of the case pathology, Dr. Yoh Zen (Department of Diagnostic Pathology, Kobe University Graduate School of Medicine), and Dr. Yoshihiro Matsuno (Department of Surgical Pathology, Hokkaido University Hospital, Sapporo, Japan) for professional advice on the case pathology.

• References

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