Case Report
Antenatal Sonographic Diagnosis of Choledochal Cyst: Case Report and Imaging Review Kyle K. Jensen, MD, Roya Sohaey, MD Oregon Health & Science University, Department of Diagnostic Radiology, Portland, OR Received 14 March 2014; accepted 16 November 2014
ABSTRACT: In this report, we present the antenatal two- and three-dimensional sonographic findings from a fetus with choledochal cyst as well as confirmatory postnatal MRI. A delayed diagnosis of choledochal cyst is common, leading to significant morbidity and mortality. Visualizing bile ducts entering a right upper quadrant cyst is pathognomonic, and early diagnosis can facilitate definitive treatment with Roux-en-Y hepaticojejunosC 2014 Wiley Periodicals, Inc. J Clin Ultrasound tomy. V 43:581–583, 2015; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/jcu.22256 Keywords: choledochal cyst; fetal diagnosis; ultrasonography; three-dimensional ultrasonography; Visser nomenclature
INTRODUCTION
C
holedochal cysts are rare congenital cystic dilatations of the extrahepatic and/or intrahepatic bile ducts.1 Their incidence is 1 in 100,000–150,000 outside Asia, where the incidence is approximately 1 in 1000.2 In this report, we present the antenatal two- and three-dimensional sonographic findings of a choledochal cyst as well as the results of a confirmatory postnatal MRI examination.
CASE REPORT
A 25-year-old gravida 2, para 0010 woman at 23 weeks, 5 days’ gestation was referred from an outside hospital after sonography (US) demonCorrespondence to: K. K. Jensen C 2014 Wiley Periodicals, Inc. V
VOL. 43, NO. 9, NOVEMBER/DECEMBER 2015
strated a right-sided abdominal cyst in the female fetus. Initial imaging at our institution revealed a 2.0 3 1.2 3 0.9-cm cyst in the liver adjacent to the neck of the gallbladder (Figure 1A). The superior aspect of the cyst was bifurcated (Figure 1B). Follow-up US examinations at 28 and 33 weeks’ gestational age demonstrated progressive enlargement of the cyst to 3.7 3 2.9 3 2.1 cm. The antenatal diagnosis of choledochal cyst type I was suggested. The neonate was delivered at 38 weeks’ gestation, and postnatal MRI was performed on day 12 of her life. The images demonstrated a type Ia choledochal cyst, the cystic subtype (Figure 1C). At the age of 2 months, our patient underwent laparoscopic cyst excision with laparoscopic Roux-en-Y hepaticojejunostomy and laparoscopic cholecystectomy with pathologic confirmation of type I choledochal cyst. The patient recovered fully and is developing appropriately. DISCUSSION
Initially described by Vater in 1723, as cited by Wang et al in 2012,3 a definitive cause of choledochal cyst development is unknown. Although many investigators have suggested an etiopathology of pancreaticobiliary maljunction and pancreatic enzyme reflux into the biliary ducts,4 this proposal is unlikely because the fetal pancreas lacks mature granules before 20 weeks’ gestational age, and these granules are at best poorly active through the remaining term of gestation.5 Other suggested causes include acquired ductal disease,4 abnormal recanalization during 581
JENSEN AND SOHAEY
FIGURE 1. (A) Transverse sonogram of the fetal abdomen at 23 weeks, 5 days’ gestational age demonstrates a 2.0 3 1.2 3 0.9-cm cyst (C) perpendicular to the gallbladder neck (GB). (B) Coronal oblique (top panel) and three-dimensional (bottom panel) sonograms demonstrate branching tubular structures (arrows) arising from the superior aspect of the cyst. (C) Coronal magnetic resonance cholangiopancreatography maximum intensity projection image demonstrates the large cyst and branching right and left hepatic ducts, superiorly (arrows). The relatively small gallbladder is also visible (arrowhead).
organogenesis,1 and biliary-duct weakness owing to abnormal epithelium.1 None of these hypotheses fully explain the 3–4:1 female and Asian predilections.2 Dewbury et al6 described the first prenatal choledochal cyst in 1980. These cysts have been diagnosed as early as 15 weeks’ gestation7 and have a variable appearance and presentation through the second and third trimesters.8 The average gestational age at diagnosis is 27 weeks.9 A delayed diagnosis is common and can result in morbidity and mortality,10 with biliary cirrhosis and portal hypertension the most common long-term sequelae.11 The mortality rate nears 100% if choledochal cyst is untreated.7 Historically, choledochal cysts were categorized into five types on the basis of the Todani modification of the Alonso-Lej classification system.2 According to this system, our case was a type Ia choledochal cyst, which is confined to the extrahepatic ducts as one of three subtypes: a, b, and c, corresponding to cystic, saccular, and fusiform extrahepatic biliary ductal dilatations.12 These three subtypes are differentiated by evaluating the relationships between the cyst, cystic duct, and gallbladder. Altogether, type 1 cysts constitute 80–90% of choledochal cysts.12 The five types described in this system are classified as follows2: 582
Type I: Cystic (Ia), fusiform (Ib), or saccular (Ic) extrahepatic biliary dilatation. Type II: Extrahepatic biliary diverticulum. Type III: Extrahepatic intraduodenal biliary tree dilatation (choledochocele). Type IV: Intrahepatic and extrahepatic cysts (IVa) or multiple extrahepatic cysts (IVb). Type V: Intrahepatic biliary cyst (Caroli disease). Currently, Visser et al13 recommend a more clinically relevant, simplified classification nomenclature. In the Visser classification system, types I and IV choledochal cysts represent a continuous spectrum of disease from extrahepatic, mixed, and completely intrahepatic lesions and require identical treatment. Therefore, the term choledochal cyst is used solely with these lesions. Previous types II, III, and V are distinct entities requiring different treatments; therefore, they are now described as choledochal diverticulum, choledochocele, and Caroli disease, respectively.13 Initial antenatal US images demonstrate a unilocular subhepatic cyst, which may contain echogenic foci.1,8 MRI may better show the T2 hyperintense bile ducts entering the choledochal cyst, and visualization of tubular bile ducts entering the right upper quadrant cyst, as seen in our case, is pathognomonic for choledochal cyst.1 JOURNAL OF CLINICAL ULTRASOUND
ANTENATAL DIAGNOSIS OF CHOLEDOCHAL CYST
When making a differential diagnosis of an antenatally detected intraabdominal cyst, one must also consider the diagnoses of choledochal cyst, hepatic cyst, enteric duplication cyst, renal cyst, ovarian cyst, and mesenteric cyst.14 Organizing the possible diagnoses according to the trimester when the cyst is discovered can be helpful. When the anomaly is detected in the second trimester, the possible diagnoses include choledochal cyst, cystic biliary atresia, and gastrointestinal duplication cyst.8 When it is detected in the third trimester, one must also consider ovarian cyst, along with gastrointestinal duplication cyst and cystic biliary atresia.14 Given the usual lack of normal gut signature in fetal bowel duplication cysts, duodenal or pyloric duplication cysts can look similar to choledochal cysts or cystic biliary atresia.15 Differentiating choledochal cyst from cystic biliary atresia is the most important and often the most difficult distinction,16 and accurate imaging is vital to prevent unnecessary surgical procedures secondary to an incorrect diagnosis of choledochal cysts, especially when compared with cystic biliary atresia.17 Casaccia et al8 recommend analyzing the cyst for echogenicity, size, and interval growth. A persistent subhepatic echogenic lesion that is found to grow on subsequent US examination with the presence of a gallbladder is suggestive of choledochal cyst, and a small subhepatic anechoic cyst without detectible gallbladder favors cystic biliary atresia. Excision of the choledochal cyst along with a Roux-en-Y hepaticojejunostomy is the definitive surgical treatment,3,7,11 and similar outcomes are obtained with both laparoscopic and open approaches.3,11 The current literature suggests a binary algorithm for treatment based on the presence or absence of symptoms, as follows: symptomatic patients receive definitive treatment before 2 months of age, with rare usage of percutaneous transhepatic cholangio-drainage, whereas asymptomatic patients are monitored closely, with definitive surgery at 6 months of age.7 In summary, making an accurate antenatal diagnosis of choledochal cyst can facilitate definitive treatment, preventing significant morbidity and mortality from delayed diagnosis.
REFERENCES 1. Woodward P, Kennedy A, Sohaey R, et al. Choledochal cyst. In: Woodward P, editor. Diagnostic Imag-
VOL. 43, NO. 9, NOVEMBER/DECEMBER 2015
ing: Obstetrics. Manitoba, Canada: Amirsys; 2011, p 76. 2. Lipsett PA, Pitt HA. Surgical treatment of choledochal cysts. J Hepatobiliary Pancreat Surg 2003;10: 352. 3. Wang B, Feng Q, Mao J. Early experience with laparoscopic excision of choledochal cyst in 41 children. J Pediatr Surg 2012;47:2175. 4. Clifton MS, Goldstein RB, Slavotinek A, et al. Prenatal diagnosis of familial type I choledochal cyst. Pediatrics 2006;117:596. 5. Schroeder D, Smith L, Prain HC. Antenatal diagnosis of choledochal cyst at 15 weeks’ gestation: etiologic implications and management. J Pediatr Surg 1989;24:936. 6. Dewbury KC, Aluwihare AP, Birch SJ, et al. Prenatal ultrasound demonstration of a choledochal cyst. Br J Radiol 1980;53:906. 7. Okada T, Sasaki F, Ueki S, et al. Postnatal management for prenatally diagnosed choledochal cysts. J Pediatr Surg 2004;39:1055. 8. Casaccia G, Bilancioni E, Nahom A, et al. Cystic anomalies of biliary tree in the fetus: is it possible to make a more specific prenatal diagnosis? J Pediatr Surg 2002;37:1191. 9. Tongprasert F, Traisrisilp K, Tongsong T. Prenatal diagnosis of choledochal cyst: a case report. J Clin Ultrasound 2012;40:48. 10. Stringer MD, Dhawan A, Davenport M, et al. Choledochal cysts: lessons from a 20 year experience. Arch Dis Child 1995;73:528. 11. Chergaoui A, Haddad M, Roman C, et al. Management of choledochal cyst: evolution with antenatal diagnosis and laparoscopic approach. J Minim Access Surg 2012;8:129. 12. Rozel C, Garel L, Rypens F, et al. Imaging of biliary disorders in children. Pediatr Radiol 2011;41: 208. 13. Visser BC, Suh I, Lawrence WW. Congenital choledochal cysts in adults. Arch Surg 2004;139:855. 14. Foley PT, Sithasanan N, McEwing R, et al. Enteric duplications presenting as antenatally detected abdominal cysts: is delayed resection appropriate? J Pediatr Surg 2003;38:1810. 15. Bancroft JD, Bucuvalas JC, Ryckman FC, et al. Antenatal diagnosis of choledochal cyst. J Pediatr Gastroenterol Nutr 1994;18:142. 16. Lee I, Kim G. Fetal choledochal cyst diagnosed at 22 weeks of gestation by three-dimensional ultrasonography: a case report. J Korean Med Sci 2008; 23:909. 17. Hinds R, Davenport M, Mieli-Vergani G, et al. Antenatal presentation of biliary atresia. Pediatrics 2004;144:43.
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Antenatal Sonographic Diagnosis of Choledochal Cyst: Case Report and Imaging Review Kyle K. Jensen, MD, Roya Sohaey, MD Oregon Health & Science University, Department of Diagnostic Radiology, Portland, OR Received 14 March 2014; accepted 16 November 2014
ABSTRACT: In this report, we present the antenatal two- and three-dimensional sonographic findings from a fetus with choledochal cyst as well as confirmatory postnatal MRI. A delayed diagnosis of choledochal cyst is common, leading to significant morbidity and mortality. Visualizing bile ducts entering a right upper quadrant cyst is pathognomonic, and early diagnosis can facilitate definitive treatment with Roux-en-Y hepaticojejunosC 2014 Wiley Periodicals, Inc. J Clin Ultrasound tomy. V 43:581–583, 2015; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/jcu.22256 Keywords: choledochal cyst; fetal diagnosis; ultrasonography; three-dimensional ultrasonography; Visser nomenclature
INTRODUCTION
C
holedochal cysts are rare congenital cystic dilatations of the extrahepatic and/or intrahepatic bile ducts.1 Their incidence is 1 in 100,000–150,000 outside Asia, where the incidence is approximately 1 in 1000.2 In this report, we present the antenatal two- and three-dimensional sonographic findings of a choledochal cyst as well as the results of a confirmatory postnatal MRI examination.
CASE REPORT
A 25-year-old gravida 2, para 0010 woman at 23 weeks, 5 days’ gestation was referred from an outside hospital after sonography (US) demonCorrespondence to: K. K. Jensen C 2014 Wiley Periodicals, Inc. V
VOL. 43, NO. 9, NOVEMBER/DECEMBER 2015
strated a right-sided abdominal cyst in the female fetus. Initial imaging at our institution revealed a 2.0 3 1.2 3 0.9-cm cyst in the liver adjacent to the neck of the gallbladder (Figure 1A). The superior aspect of the cyst was bifurcated (Figure 1B). Follow-up US examinations at 28 and 33 weeks’ gestational age demonstrated progressive enlargement of the cyst to 3.7 3 2.9 3 2.1 cm. The antenatal diagnosis of choledochal cyst type I was suggested. The neonate was delivered at 38 weeks’ gestation, and postnatal MRI was performed on day 12 of her life. The images demonstrated a type Ia choledochal cyst, the cystic subtype (Figure 1C). At the age of 2 months, our patient underwent laparoscopic cyst excision with laparoscopic Roux-en-Y hepaticojejunostomy and laparoscopic cholecystectomy with pathologic confirmation of type I choledochal cyst. The patient recovered fully and is developing appropriately. DISCUSSION
Initially described by Vater in 1723, as cited by Wang et al in 2012,3 a definitive cause of choledochal cyst development is unknown. Although many investigators have suggested an etiopathology of pancreaticobiliary maljunction and pancreatic enzyme reflux into the biliary ducts,4 this proposal is unlikely because the fetal pancreas lacks mature granules before 20 weeks’ gestational age, and these granules are at best poorly active through the remaining term of gestation.5 Other suggested causes include acquired ductal disease,4 abnormal recanalization during 581
JENSEN AND SOHAEY
FIGURE 1. (A) Transverse sonogram of the fetal abdomen at 23 weeks, 5 days’ gestational age demonstrates a 2.0 3 1.2 3 0.9-cm cyst (C) perpendicular to the gallbladder neck (GB). (B) Coronal oblique (top panel) and three-dimensional (bottom panel) sonograms demonstrate branching tubular structures (arrows) arising from the superior aspect of the cyst. (C) Coronal magnetic resonance cholangiopancreatography maximum intensity projection image demonstrates the large cyst and branching right and left hepatic ducts, superiorly (arrows). The relatively small gallbladder is also visible (arrowhead).
organogenesis,1 and biliary-duct weakness owing to abnormal epithelium.1 None of these hypotheses fully explain the 3–4:1 female and Asian predilections.2 Dewbury et al6 described the first prenatal choledochal cyst in 1980. These cysts have been diagnosed as early as 15 weeks’ gestation7 and have a variable appearance and presentation through the second and third trimesters.8 The average gestational age at diagnosis is 27 weeks.9 A delayed diagnosis is common and can result in morbidity and mortality,10 with biliary cirrhosis and portal hypertension the most common long-term sequelae.11 The mortality rate nears 100% if choledochal cyst is untreated.7 Historically, choledochal cysts were categorized into five types on the basis of the Todani modification of the Alonso-Lej classification system.2 According to this system, our case was a type Ia choledochal cyst, which is confined to the extrahepatic ducts as one of three subtypes: a, b, and c, corresponding to cystic, saccular, and fusiform extrahepatic biliary ductal dilatations.12 These three subtypes are differentiated by evaluating the relationships between the cyst, cystic duct, and gallbladder. Altogether, type 1 cysts constitute 80–90% of choledochal cysts.12 The five types described in this system are classified as follows2: 582
Type I: Cystic (Ia), fusiform (Ib), or saccular (Ic) extrahepatic biliary dilatation. Type II: Extrahepatic biliary diverticulum. Type III: Extrahepatic intraduodenal biliary tree dilatation (choledochocele). Type IV: Intrahepatic and extrahepatic cysts (IVa) or multiple extrahepatic cysts (IVb). Type V: Intrahepatic biliary cyst (Caroli disease). Currently, Visser et al13 recommend a more clinically relevant, simplified classification nomenclature. In the Visser classification system, types I and IV choledochal cysts represent a continuous spectrum of disease from extrahepatic, mixed, and completely intrahepatic lesions and require identical treatment. Therefore, the term choledochal cyst is used solely with these lesions. Previous types II, III, and V are distinct entities requiring different treatments; therefore, they are now described as choledochal diverticulum, choledochocele, and Caroli disease, respectively.13 Initial antenatal US images demonstrate a unilocular subhepatic cyst, which may contain echogenic foci.1,8 MRI may better show the T2 hyperintense bile ducts entering the choledochal cyst, and visualization of tubular bile ducts entering the right upper quadrant cyst, as seen in our case, is pathognomonic for choledochal cyst.1 JOURNAL OF CLINICAL ULTRASOUND
ANTENATAL DIAGNOSIS OF CHOLEDOCHAL CYST
When making a differential diagnosis of an antenatally detected intraabdominal cyst, one must also consider the diagnoses of choledochal cyst, hepatic cyst, enteric duplication cyst, renal cyst, ovarian cyst, and mesenteric cyst.14 Organizing the possible diagnoses according to the trimester when the cyst is discovered can be helpful. When the anomaly is detected in the second trimester, the possible diagnoses include choledochal cyst, cystic biliary atresia, and gastrointestinal duplication cyst.8 When it is detected in the third trimester, one must also consider ovarian cyst, along with gastrointestinal duplication cyst and cystic biliary atresia.14 Given the usual lack of normal gut signature in fetal bowel duplication cysts, duodenal or pyloric duplication cysts can look similar to choledochal cysts or cystic biliary atresia.15 Differentiating choledochal cyst from cystic biliary atresia is the most important and often the most difficult distinction,16 and accurate imaging is vital to prevent unnecessary surgical procedures secondary to an incorrect diagnosis of choledochal cysts, especially when compared with cystic biliary atresia.17 Casaccia et al8 recommend analyzing the cyst for echogenicity, size, and interval growth. A persistent subhepatic echogenic lesion that is found to grow on subsequent US examination with the presence of a gallbladder is suggestive of choledochal cyst, and a small subhepatic anechoic cyst without detectible gallbladder favors cystic biliary atresia. Excision of the choledochal cyst along with a Roux-en-Y hepaticojejunostomy is the definitive surgical treatment,3,7,11 and similar outcomes are obtained with both laparoscopic and open approaches.3,11 The current literature suggests a binary algorithm for treatment based on the presence or absence of symptoms, as follows: symptomatic patients receive definitive treatment before 2 months of age, with rare usage of percutaneous transhepatic cholangio-drainage, whereas asymptomatic patients are monitored closely, with definitive surgery at 6 months of age.7 In summary, making an accurate antenatal diagnosis of choledochal cyst can facilitate definitive treatment, preventing significant morbidity and mortality from delayed diagnosis.
REFERENCES 1. Woodward P, Kennedy A, Sohaey R, et al. Choledochal cyst. In: Woodward P, editor. Diagnostic Imag-
VOL. 43, NO. 9, NOVEMBER/DECEMBER 2015
ing: Obstetrics. Manitoba, Canada: Amirsys; 2011, p 76. 2. Lipsett PA, Pitt HA. Surgical treatment of choledochal cysts. J Hepatobiliary Pancreat Surg 2003;10: 352. 3. Wang B, Feng Q, Mao J. Early experience with laparoscopic excision of choledochal cyst in 41 children. J Pediatr Surg 2012;47:2175. 4. Clifton MS, Goldstein RB, Slavotinek A, et al. Prenatal diagnosis of familial type I choledochal cyst. Pediatrics 2006;117:596. 5. Schroeder D, Smith L, Prain HC. Antenatal diagnosis of choledochal cyst at 15 weeks’ gestation: etiologic implications and management. J Pediatr Surg 1989;24:936. 6. Dewbury KC, Aluwihare AP, Birch SJ, et al. Prenatal ultrasound demonstration of a choledochal cyst. Br J Radiol 1980;53:906. 7. Okada T, Sasaki F, Ueki S, et al. Postnatal management for prenatally diagnosed choledochal cysts. J Pediatr Surg 2004;39:1055. 8. Casaccia G, Bilancioni E, Nahom A, et al. Cystic anomalies of biliary tree in the fetus: is it possible to make a more specific prenatal diagnosis? J Pediatr Surg 2002;37:1191. 9. Tongprasert F, Traisrisilp K, Tongsong T. Prenatal diagnosis of choledochal cyst: a case report. J Clin Ultrasound 2012;40:48. 10. Stringer MD, Dhawan A, Davenport M, et al. Choledochal cysts: lessons from a 20 year experience. Arch Dis Child 1995;73:528. 11. Chergaoui A, Haddad M, Roman C, et al. Management of choledochal cyst: evolution with antenatal diagnosis and laparoscopic approach. J Minim Access Surg 2012;8:129. 12. Rozel C, Garel L, Rypens F, et al. Imaging of biliary disorders in children. Pediatr Radiol 2011;41: 208. 13. Visser BC, Suh I, Lawrence WW. Congenital choledochal cysts in adults. Arch Surg 2004;139:855. 14. Foley PT, Sithasanan N, McEwing R, et al. Enteric duplications presenting as antenatally detected abdominal cysts: is delayed resection appropriate? J Pediatr Surg 2003;38:1810. 15. Bancroft JD, Bucuvalas JC, Ryckman FC, et al. Antenatal diagnosis of choledochal cyst. J Pediatr Gastroenterol Nutr 1994;18:142. 16. Lee I, Kim G. Fetal choledochal cyst diagnosed at 22 weeks of gestation by three-dimensional ultrasonography: a case report. J Korean Med Sci 2008; 23:909. 17. Hinds R, Davenport M, Mieli-Vergani G, et al. Antenatal presentation of biliary atresia. Pediatrics 2004;144:43.
583
