Figure 1
7th day of life ultrasound - thin-walled, anechoic cystic lesion located anteriorly to the portal vein, in the porta hepatis. The lesion was presumed to be Todani’s type Ib/Ic choledochal cyst.
Cystic Biliary Atresia: an uncommon variant of biliary atresia in which a gallbladder may be present
SectionPaediatric radiology
Case TypeClinical Cases
Authors
Prata, Rita1; Nunes, Ana1; Borges, Cristina2; Soares, Eugénia1
Connected authors
45 days, female
Clinical History
A female newborn with a cystic abdominal lesion identified on a prenatal screening ultrasound was admitted to the emergency department on her 45th day of life with depigmented stools and increased jaundice noticed for 2 days previously to the admission.
Imaging Findings
Abdominal ultrasound demonstrated a cystic lesion in the porta hepatis as well as a probable triangular cord sign and an irregular walled distended elongated gallbladder.
Given the undetermined cholestatic clinical picture and the possible hypothesis of biliary atresia which should be surgically corrected on the first 2 months of age to prevent hepatic cirrhosis [1], a multidisciplinary meeting decided to do an intraoperatory cholangiogram and exploratory surgery.
She underwent surgery on her 60th day of life. On the abdominal inspection a green-coloured augmented volume liver was seen along with an elongated and distended gallbladder which was in continuity with a cystic lesion located on the hepatoduodenal ligament. An intraoperatory cholangiogram was performed (figure 4) with water-soluble iodinated contrast material. There was no passage of contrast media to the intrahepatic duct or passage to the duodenal lumen.
Discussion
Background
Biliary atresia (BA) is a neonatal diagnosis resulting from progressive fibrosis with narrowing and obliteration of the intra- and extra-hepatic bile ducts[2]. Kasai portoenterostomy should be performed in the first 2 months of age [1] to avoid hepatic cirrhosis. In 8% [2] of the cases, BA may present as a cystic variant known as cystic BA with which the differential diagnosis of choledochal cyst should be made. In cystic BA a cystic change is observed in the extrahepatic bile ducts in an otherwise obliterated biliary tract. Choledochal cysts can be asymptomatic, present as an abdominal mass or with the same clinical picture as BA (cholestatic jaundice)[2]. The cyst represents a congenital dilatation of the biliary tree with the remaining ducts patent or even dilated. Distinguishing between these entities is critically important as their surgical management (both the timing and procedure) are different.
Clinical Perspective
Ultrasound is the modality of choice to differentiate between obstructive and non-obstructive hyperbilirubinemia[2,3]. In the case of a non-diagnostic ultrasound, an intraoperative cholangiogram may help.[3]
Imaging Perspective
In our patient, the presence of a cyst in the porta hepatis, anterior to the portal vein suggested a choledochal cyst. However, an equivocal cord sign (3,4mm anterior to the right portal vein) was possible to visualize in the documented images, raising question about the possibility of BA. The visualization of a distended elongated gallbladder was a confounding factor for the assumption of the diagnosis of BA. However, irregular internal walls should be noted (fig.3a) and according to the classification suggested by Zhou[4], type IV gallbladders with a length-to-width ratio > 5.2 (as in this case (5,3)) could suggest biliary atresia.
Findings in favor of: (1) choledochal cyst: intrahepatic bile duct dilation, a normal-sized (defined as gallbladder length of 1.5 cm or greater) or distended gallbladder[6,7]. (2) cystic BA: atretic or irregularly elongated gallbladder, presence of the triangular cord sign (defined as thickness of the anterior echogenic wall of the right portal vein just proximal to the right portal vein bifurcation site of greater than 4 mm[5, 6]), the absence of gallstones and sludge within the cyst at the hepatic hilum[6,7]
Outcome
An intraoperative cholangiogram (fig.4) confirmed the diagnosis, Kasai portoenterostomy was performed and the cholestatic picture resolved.
Take-Home Message / Teaching Points
Even when a fully distended gallbladder is identified, do not exclude the hypothesis of biliary atresia.
Written informed patient consent for publication has been obtained.
Differential Diagnosis List
Cystic biliary atresia
Todani’s type Ib/Ic choledochal cyst
Final Diagnosis
Cystic biliary atresia
References
[1] Chardot, C., (2006) Biliary atresia. Orphanet J Rare Dis, 1: p. 28. (PMID: 16872500)
[2] Shamir, S.B., et al., (2017) Hepatic Imaging in Neonates and Young Infants: State of the Art. Radiology, 285(3): p. 763-777. (PMID: 29155636)
[3] Gotze, T., et al., (2015) Neonatal Cholestasis - Differential Diagnoses, Current Diagnostic Procedures, and Treatment. Front Pediatr, 3: p. 43. (PMID: 26137452)
[4] Zhou, L.Y., et al., (2015) Optimizing the US Diagnosis of Biliary Atresia with a Modified Triangular Cord Thickness and Gallbladder Classification. Radiology, 277(1): p. 181-91.(PMID: 25955579)
[5] Lee, H.J., et al.,(2003) Objective criteria of triangular cord sign in biliary atresia on US scans. Radiology, 229(2): p. 395-400. (PMID: 14595143)
[6] Zhou, L.Y., et al., (2012) Objective differential characteristics of cystic biliary atresia and choledochal cysts in neonates and young infants: sonographic findings. J Ultrasound Med, 31(6): p. 833-41. (PMID: 22644679)
[7] Kim, W.S., et al., (1998) Choledochal cyst with or without biliary atresia in neonates and young infants: US differentiation. Radiology, 209(2): p. 465-9. (PMID: 9807575)
Case information
| URL: | https://eurorad.org/case/17203 |
| DOI: | 10.35100/eurorad/case.17203 |
| ISSN: | 1563-4086 |
License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Figure 2
52nd day of life ultrasound. Fig 2a - Cystic lesion on the choledochal duct topography and unsatisfactory distension of the gallbladder. Fig. 2b - A possible chord sign was reported (3,4mm anterior to the right portal vein). It was recommended to revaluate the child’s gallbladder after a prolonged fast given the possible diagnosis of biliary atresia.
52nd day of life ultrasound. Fig 2a - Cystic lesion on the choledochal duct topography and unsatisfactory distension of the gallbladder. Fig. 2b - A possible chord sign was reported (3,4mm anterior to the right portal vein). It was recommended to revaluate the child’s gallbladder after a prolonged fast given the possible diagnosis of biliary atresia.
Figure 3
54th day of life (7 weeks) ultrasound after a 10-hour fast. A distended elongated gallbladder with irregular internal walls with an approximated volume of 1,6cc was documented with a length-to width ratio of 5.3(Fig. 3a). The cystic lesion with the same characteristics (Fig. 3b) and an equivocal triangular cord sign (Fig. 3c) was described.
54th day of life (7 weeks) ultrasound after a 10-hour fast. A distended elongated gallbladder with irregular internal walls with an approximated volume of 1,6cc was documented with a length-to width ratio of 5.3(Fig. 3a). The cystic lesion with the same characteristics (Fig. 3b) and an equivocal triangular cord sign (Fig. 3c) was described.
54th day of life (7 weeks) ultrasound after a 10-hour fast. A distended elongated gallbladder with irregular internal walls with an approximated volume of 1,6cc was documented with a length-to width ratio of 5.3(Fig. 3a). The cystic lesion with the same characteristics (Fig. 3b) and an equivocal triangular cord sign (Fig. 3c) was described.
Figure 4
Fluoroscopic image obtained during intraoperatory cholangiogram performed to assess patency of the intra- and extrahepatic bile ducts. The gallbladder was percutaneously accessed with a flexible catheter. Image shows opacification of the gallbladder, cystic duct and the cystic lesion documented on the ultrasound. There was no passage of contrast media to the intrahepatic duct nor passage to the duodenal lumen. A cystic biliary atresia diagnosis was assumed.
7th day of life ultrasound - thin-walled, anechoic cystic lesion located anteriorly to the portal vein, in the porta hepatis. The lesion was presumed to be Todani’s type Ib/Ic choledochal cyst.
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019
52nd day of life ultrasound. Fig 2a - Cystic lesion on the choledochal duct topography and unsatisfactory distension of the gallbladder. Fig. 2b - A possible chord sign was reported (3,4mm anterior to the right portal vein). It was recommended to revaluate the child’s gallbladder after a prolonged fast given the possible diagnosis of biliary atresia.
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019
52nd day of life ultrasound. Fig 2a - Cystic lesion on the choledochal duct topography and unsatisfactory distension of the gallbladder. Fig. 2b - A possible chord sign was reported (3,4mm anterior to the right portal vein). It was recommended to revaluate the child’s gallbladder after a prolonged fast given the possible diagnosis of biliary atresia.
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019
54th day of life (7 weeks) ultrasound after a 10-hour fast. A distended elongated gallbladder with irregular internal walls with an approximated volume of 1,6cc was documented with a length-to width ratio of 5.3(Fig. 3a). The cystic lesion with the same characteristics (Fig. 3b) and an equivocal triangular cord sign (Fig. 3c) was described.
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019
54th day of life (7 weeks) ultrasound after a 10-hour fast. A distended elongated gallbladder with irregular internal walls with an approximated volume of 1,6cc was documented with a length-to width ratio of 5.3(Fig. 3a). The cystic lesion with the same characteristics (Fig. 3b) and an equivocal triangular cord sign (Fig. 3c) was described.
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019
54th day of life (7 weeks) ultrasound after a 10-hour fast. A distended elongated gallbladder with irregular internal walls with an approximated volume of 1,6cc was documented with a length-to width ratio of 5.3(Fig. 3a). The cystic lesion with the same characteristics (Fig. 3b) and an equivocal triangular cord sign (Fig. 3c) was described.
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019
Fluoroscopic image obtained during intraoperatory cholangiogram performed to assess patency of the intra- and extrahepatic bile ducts. The gallbladder was percutaneously accessed with a flexible catheter. Image shows opacification of the gallbladder, cystic duct and the cystic lesion documented on the ultrasound. There was no passage of contrast media to the intrahepatic duct nor passage to the duodenal lumen. A cystic biliary atresia diagnosis was assumed.
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019
Department of Radiology, Dona Estefânia Pediatric Hospital, Lisbon, Portugal, 2019