788 Gidi ADG, et al. , 2016; 15 (5): 788-794 CASE REPORT September-October, Vol. 15 No. 5, 2016: 788-794 The Official Journal of the Mexican Association of Hepatology, the Latin-American Association for Study of the Liver and the Canadian Association for the Study of the Liver An unusual type of biliar cyst: A case report Alejandro D. G. Gidi,* Mario A. González-Chávez,* Eduardo Villegas-Tovar,*,, Víctor Visag-Castillo,* Juan P. Pantoja-Millan,* Francisco M. Vélez-Pérez,* Fernando Cano-García,** Alan G. Contreras* * Department of Surgery, Medica Sur Hospital, Mexico City. ** Department of Pathology, Medica Sur Hospital, Mexico City. ABSTRACT We present the case of a 56-yr-old woman with vague abdominal pain of approximately 5 months duration. An ultrasound study showed moderate dilation of the common bile duct. Magnetic resonance cholangiopancreatography confirmed a cystic dilatation of the right hepatic duct with intra and extra hepatic component. The patient underwent right hepatectomy and complete excision of the cyst. Microscopically, the cyst wall was formed by fibrous tissue with mild acute and chronic inflammatory infiltrate, the inner surface showed a single layer of columnar epithelium and extensive squamous metaplasia without atypia, wich expressed p63 and high mo- lecular weight cytoqueratin (34BE12). Key words.words.Key Choledochal cyst. Bile duct cysts. Classification. Management. INTRODUCTION There was no evidence of jaundice or palpable abdomi- nal mass on physical examination. She had mild tender- Choledochal cysts (CC) are rare medical conditions ness at the right upper quadrant but no Murphy’s sign. An and consist of cystic dilatations of the extrahepatic biliary ultrasound study showed moderate dilation of the com- tree, intrahepatic biliary ducts or both, with an incidence mon bile duct and a large cystic mass of unclear origin in in the western population of 1 in 100,000-150,000 live the liver, there was no certainty that the cyst continue births, although the incidence has been reported to be as to the intrahepatic bile tract (Figure 1). A magnetic reso- high as 1 in 13,500 births in the United States and 1 in nance cholangiopancreatography was obtained to help 15,000 births in Australia.1 The rate is remarkably higher clarify the anatomy. The magnetic resonance cholangio- in Asian populations with a reported incidence of 1 in 1000, and about two thirds of cases occur in Japan. The rea- son for this Asian preponderance is still unclear. There is also an unexplained female:male preponderance, com- monly reported as 4:1 or 3:1.2. CC are classified into five main types with several sub- types. Anatomical configurations, which do not readily fall into the Todani modification, have been described.3 CYSTCYSTCYST CASE REPORT A 56-yr-old woman presented initially complaining of vague abdominal pain of approximately 5 months duration. She denied nausea, vomiting, or weight loss, and had a normal ap- petite. She had no other medical problems, took no medica- Figure 1.1.Figure Ultrasound showing moderate dilation of the common bile duct tions regularly, and she had no previous surgical procedures. and a large cystic mass. Arrow showing gallbladder. Manuscript received: January 26, 2016. Manuscript accepted: April 06, 2016. DOI:10.5604/16652681.1212618. An unusual type of biliar cyst. , 2016; 15 (5): 788-794 789 Figure 2.2.Figure Magnetic resonance cholangiopancreatography confirmed a cys- tic dilatation of the right hepatic duct (arrow) next to the gallbladder (point of Figure 4. In the surgical exploration post-resection of the gallbladder, a arrow); the head of the pancreas appeared normal. cystic mass under the right hepatic duct was observed (arrow). tomy was performed (Figure 4). There were no intraoper- ative complications. The specimen consisted of an 18.2 cm liver and biliary duct segment; a 5.6 cm unilocular cyst was identified on the right hepatic duct, the external surface was regular and green, in the inner surface solid areas were not identified. Microscopically, the cyst wall was formed by fibrous tissue with mild acute and chronic in- flammatory infiltrate, the inner surface showed a single layer of columnar epithelium and extensive squamous metaplasia without atypia, which expressed p63 and high molecular weight cytoqueratin (34BE12). The residual in- ner parenchymal was normal (Figure 5). The patient expe- rienced a full recovery and was discharged on postoperative day 5. DISCUSSION Figure 3.3.Figure MR cholangiopancreatography show cystic dilatation of right bile CC are rare congenital cystic dilation of the biliary duct. tract, first described by Vater and Ezler in 1723.4 They present primarily in female infants and young children and pancreatography showed a cystic dilatation of the right he- are more prevalent in East Asian populations. Although be- patic duct with intra and extra hepatic component, the nign, CC can be associated with serious complications in- head of the pancreas appeared normal, as did the stomach, cluding malignant transformation, cholangitis, pancreatitis, kidney, liver, and adrenal gland. There were no other ab- and cholelithiasis.5 normalities (Figures 2 and 3). The patient underwent ex- Approximately 80% of the CC are diagnosed in infants ploratory laparotomy through a supraumbilical middle and young children within the first decade of life. The in- line incision. The gallbladder was removed and a sacular cidence of CC ranges from 1 in 100,000 to 1 in 150,000 dilatation of the right hepatic duct was observed after the individuals in Western countries and 1 in 13,000 individu- removal of the gallblader. The right bile duct was transect- als in Japan.6 CC are 4 times more common in females.1,6 ed distally, at the level of the confluence. Small duct Although the exact etiology is unknown, anomalous pan- stones were found inside the right hepatic duct. The left creaticobiliary duct union (APBDU) is seen in 30% to and common bile ducts remained intact. A right hepatec- 70% of all CC where the common bile duct (CBD) and 790 Gidi ADG, et al. , 2016; 15 (5): 788-794 AAA BBB CCC DDD Figure 5. The photomicrograph shows the fibrous cystic wall (A) wich inner sur- face is covered by columnar epithelium (B) with extensive squamous metaplasia (C) The metaplastic cells expressed p63 (D) and high molecular weight cytoque- ratin. pancreatic duct junction occurs outside the duodenum, al- patic or common bile duct; type III (also known as lowing reflux of pancreatic fluid into the biliary tree.7 choledochocele), an intraduodenal diverticulum of the It is well accepted that a CC is a premalignant state. distal common bile duct; type IV, intrahepatic and extra- The overall risk of cancer has been reported to be 10%- hepatic fusiform cysts (IVA), or multiple extrahepatic 15%, and increases with age. The risk rises from 2.3% in cysts (IVB); type V (also known as Caroli’s disease), mul- patients aged 20-30 years to 75% in patients aged 70-80 tiple intrahepatic cysts. The classification of bile duct years, and histopathology shows increasing dysplasia with cysts is important as it guides the clinical management and increasing age. Distribution of the types of cancer found may provide prognostic information.10 in patients with CC are as follows: adenocarcinoma In a recent review of the literature, the relative frequen- 73%-84%, anaplastic carcinoma 10%, undifferentiated car- cy of bile duct cysts using the Todani classification is type cinoma 5%-7%, squamous cell carcinoma 5% and other I (78%), type II (3%), type III (3%), type IV (15%), and carcinoma 1.5%.8 type V (1%). Intrahepatic variants of bile duct cysts with Bile duct cysts are classified based on location, extent isolated saccular or fusiform cysts arising from the main and shape of the cystic anomaly within the bile duct sys- lobar bile ducts near the confluence have been noted anec- tem. Currently, Todani’s modification3 of the Alonso-Lej dotally and are not classifiable by current typing schemes. classification9 is most commonly used which includes Whether these cysts are true bile duct cysts or cystadeno- both extrahepatic and intrahepatic bile duct cysts and the ma variants isn unk own.11 variants of Caroli’s disease (Figure 6). This classification CC in our patient was classified as Todani type IV, but includes five types: type I, a solitary fusiform or saccular the morphology of the cysts was unusual. The cyst only dilation of the common hepatic and common bile duct; took part of the right hepatic duct and its location was to- type II, a supraduodenal diverticulum of the common he- tally intrahepatic. Because of this, it is not in any classifi- An unusual type of biliar cyst. , 2016; 15 (5): 788-794 791 Figure 6. Todani’s classification of choledochal cysts. cation and malignant potential was unknown so a wider Abdominal pain is the most common symptom in adult resection was considered. This variant of CC has not been patients, with an incidence ranging from 78% to 90%. recognized previously and we propose the classification of Jaundice, nausea, and cholangitis are found in 40%-50% of this variant under Todani’s system, as type IVC. Surgeons adults. Cholangitis or pancreatitis is a common symptom should be aware of the possibility of variant anatomy in in adult. Dilatation of the bile ducts and stricture cause choledochal cysts, which is outside the normal classifica- bile stasis, stone or sludge formation, resulting in ascend- tion for this condition. ing cholangitis or pancreatitis.12 Clinical presentation varies with age, and 80% of the With the increased use of axial imaging, more CC are be- patients present before the age of 10 years. Children usual- ing diagnosed as incidental findings. CC diagnosis is typi- ly have signs and symptoms, but adults are asymptomatic.