**8. Diagnostic evaluation**

Ultimately, multimodality imaging techniques are often utilized including computed tomography (CT), magnetic resonance imaging (MRI), and/or endoscopic retrograde cholangiopancreatography (ERCP) to confirm the extent of ductal involvement or the presence of extrahepatic disease [25]. Frequently, further imaging techniques are used to differentiate type I CC from type IVa, in the presence of intrahepatic biliary dilatation [11]. A cyst, presenting in the porta hepatitis, separated from the gallbladder and continuing with enlarged biliary ducts can be shown by ultrasound (US). Additionally, fusiform dilatation of choledoch, intrahepatic biliary dilatation (60–80%), biliary stones, and state of liver parenchyma can be shown by US [86].

Other intraabdominal cysts, such as pancreatic pseudocysts, echinococcal cysts, or biliary cystadenomas should also be differentiated from CCs, whether the cyst has continuity with the biliary tree or not [40]. CT is not only useful for demonstrating continuity of the cyst with the biliary tree, but also demonstrates relation of the cyst with the surrounding structures and the presence of associated malignancy [87]. In order to correctly plan surgery, CT cholangiography can be used to identify the full anatomy of the biliary tree but unfortunately it has been reported to be less sensitive for imaging the pancreatic duct which is responsible for the reflux of contrast into the biliary ducts [87]. As it is well known today, the nephrohepatotoxicity of the contrast and the ionized radiation exposed are the restrictions of CT utilization in pediatric population (**Figure 3**) [62].

MRCP is noninvasive and highly sensitive (70–100%) and specific (90–100%) in the diagnosis of CCs [88, 89], so, is considered the current gold standard imaging even for initial evaluation [62]. Additionally, there is no irradiation, and modern scanners have alleviated the need for protracted breath-hold making it more amenable to the pediatric population [10, 90]. Although both ultrasound and CT are highly sensitive and specific in the diagnosis of CCs, MRCP can better identify the CCs subtypes and coexisting abnormalities [89]. For example, MRI can easily identify the pancreaticobiliary ductal anatomy, while ultrasound cannot accurately demonstrate the APBDU [89, 91]. Additionally, MRCP is preferred modality in the pediatric population due to invasive nature and inherent risks of endoscopic ultrasound and ERCP, despite their ability of detecting the abnormality of the common

**Figure 3.** *Type III CC. (a) MRCP; (b) CT image.*

channel [89]. MRCP has also been shown to be as effective as intraoperative cholangiography in planning surgery [18]. In addition, lower cost and morbidity compared to other imaging/diagnostic modalities, and reliability for detecting abnormalities associated with CCs such as cholangiocarcinoma and choledocholithiasis, are some of the favorable features of MRCP [89, 92]. Unfortunately, as seen often in patients with CCs, intraductal air, debris, stones, or protein plugs can interfere with the signal and alter visualization (**Figure 4**) [93].

Although it is highly sensitive, invasiveness and associated risks including cholangitis, bleeding, pancreatitis, and perforation makes percutaneous transhepatic cholangiography (PTC) or ERCP utilization less frequently [94]. Moreover, PTC and ERCP can be technically challenging and require general anesthesia in the pediatric population. A lot of surgeons are finding the use of diagnostic ERCP and PTC in CCs unnecessary due to advantages of both MRCP and perioperative cholangiography (performed in nearly almost patients and give highly detailed information about

**95**

*Pediatric Choledochal Cysts: Unknowns are Decreasing DOI: http://dx.doi.org/10.5772/intechopen.84301*

**8.1 The differential diagnosis**

necessary [107].

biliary anatomy) [10, 95, 96]. Contemporary, ERCP should only be performed in cases where the appropriate diagnosis cannot be made by other less-invasive examinations, or when therapeutic performance (complications such as cholangitis or biliary stone obstruction [97, 98] and stabilization of the patients with preparing

Another method that is not preferred now for diagnostic purposes is hepatobiliary scintigraphy. Although it is possible to do it with all IDA variants, DISIDA is the best. The radio isotopic substance is collected in the liver and is normally thrown into the biliary tract, but accumulates in the cyst space in patients with CC [101, 102].

There are many diseases including biliary atresia, infectious hepatitis, embryonal hepatic rhabdomyosarcoma, biliary lithiasis, pancreatitis, biliary hamartoma in the differential diagnosis of CCs, especially biliary atresia that is one of the two causes of neonatal obstructive jaundice in neonatal period [10]. Differentiating cystic biliary atresia (CBA), a subtype of biliary atresia and has an entirely different treatment approach, from CCs is particularly difficult. Therefore, prompt accurate diagnosis is critical [103]. While earlier presentation (<months of age), smaller cysts with less dilatation of the intrahepatic biliary system, and an atretic gallbladder with irregular and hypoplastic biliary radicles that is seen on ultrasound and cholangiography are characteristics of CBA patients [10, 20, 104, 105]; a dilated gallbladder communicated with the cyst in addition with a dilated intrahepatic

It is still important to differentiate biliary rhabdomyosarcoma, a rare soft tissue tumor that affects only 1% of children, from CC [106, 107]. In the presence of a mass or intraductal growth that causes obstructive jaundice, the possible diagnosis should return in favor of rhabdomyosarcoma in children and prompt evaluation is

"Children with CBD dilatation did not differ significantly in clinical characteristics compared with children who had obstructive CBD dilatation" said Oh and colleagues [78] by evaluating the cholangiographic characteristics of 85 children with CBD dilatation to differentiate obstructive and congenital CBD dilatation. Indeed, it can be difficult to distinguish them. Therefore, in the pediatric population with dilated biliary trees, ruling out a distal biliary obstruction that causes secondary

As noted above, type I CC may present with intrahepatic biliary dilatation secondary to biliary stasis, thus resembling a type IVa CC. Some authors consider that this distinction is critical given the therapeutic implications and the need to include hepatic resection (in the case of type IVa CC) in addition to extrahepatic biliary tree excision [18], whereas the others consider that the need preoperatively distinguishing between type I and IVa CCs is controversial because for both, complete excision of the extrahepatic bile duct and intensive long-term follow-up

The treatment time of antenatal diagnosed of CCs has been still a matter of debate. Some reports say that they can be operated within 2–6 weeks, even if they are asymptomatic, due to a potential complication risk of cysts, whereas, the others suggest that they can be followed-up for a time of period with US and regular

them to the next definitive surgery) is required (**Figure 4**) [39, 99, 100].

biliary tree is mostly a determiner to infantile CC [104].

biliary dilatation is prudent and essential [18].

remains standard of care [11].

monitoring of liver functions [108, 109].

**9. Management**

**Figure 4.** *PTC reveals the detailed anatomy of the biliary tracts and associated CC.*

biliary anatomy) [10, 95, 96]. Contemporary, ERCP should only be performed in cases where the appropriate diagnosis cannot be made by other less-invasive examinations, or when therapeutic performance (complications such as cholangitis or biliary stone obstruction [97, 98] and stabilization of the patients with preparing them to the next definitive surgery) is required (**Figure 4**) [39, 99, 100].

Another method that is not preferred now for diagnostic purposes is hepatobiliary scintigraphy. Although it is possible to do it with all IDA variants, DISIDA is the best. The radio isotopic substance is collected in the liver and is normally thrown into the biliary tract, but accumulates in the cyst space in patients with CC [101, 102].

### **8.1 The differential diagnosis**

*Pediatric Surgery, Flowcharts and Clinical Algorithms*

signal and alter visualization (**Figure 4**) [93].

*PTC reveals the detailed anatomy of the biliary tracts and associated CC.*

**Figure 3.**

*Type III CC. (a) MRCP; (b) CT image.*

channel [89]. MRCP has also been shown to be as effective as intraoperative cholangiography in planning surgery [18]. In addition, lower cost and morbidity compared to other imaging/diagnostic modalities, and reliability for detecting abnormalities associated with CCs such as cholangiocarcinoma and choledocholithiasis, are some of the favorable features of MRCP [89, 92]. Unfortunately, as seen often in patients with CCs, intraductal air, debris, stones, or protein plugs can interfere with the

Although it is highly sensitive, invasiveness and associated risks including cholangitis, bleeding, pancreatitis, and perforation makes percutaneous transhepatic cholangiography (PTC) or ERCP utilization less frequently [94]. Moreover, PTC and ERCP can be technically challenging and require general anesthesia in the pediatric population. A lot of surgeons are finding the use of diagnostic ERCP and PTC in CCs unnecessary due to advantages of both MRCP and perioperative cholangiography (performed in nearly almost patients and give highly detailed information about

**94**

**Figure 4.**

There are many diseases including biliary atresia, infectious hepatitis, embryonal hepatic rhabdomyosarcoma, biliary lithiasis, pancreatitis, biliary hamartoma in the differential diagnosis of CCs, especially biliary atresia that is one of the two causes of neonatal obstructive jaundice in neonatal period [10]. Differentiating cystic biliary atresia (CBA), a subtype of biliary atresia and has an entirely different treatment approach, from CCs is particularly difficult. Therefore, prompt accurate diagnosis is critical [103]. While earlier presentation (<months of age), smaller cysts with less dilatation of the intrahepatic biliary system, and an atretic gallbladder with irregular and hypoplastic biliary radicles that is seen on ultrasound and cholangiography are characteristics of CBA patients [10, 20, 104, 105]; a dilated gallbladder communicated with the cyst in addition with a dilated intrahepatic biliary tree is mostly a determiner to infantile CC [104].

It is still important to differentiate biliary rhabdomyosarcoma, a rare soft tissue tumor that affects only 1% of children, from CC [106, 107]. In the presence of a mass or intraductal growth that causes obstructive jaundice, the possible diagnosis should return in favor of rhabdomyosarcoma in children and prompt evaluation is necessary [107].

"Children with CBD dilatation did not differ significantly in clinical characteristics compared with children who had obstructive CBD dilatation" said Oh and colleagues [78] by evaluating the cholangiographic characteristics of 85 children with CBD dilatation to differentiate obstructive and congenital CBD dilatation. Indeed, it can be difficult to distinguish them. Therefore, in the pediatric population with dilated biliary trees, ruling out a distal biliary obstruction that causes secondary biliary dilatation is prudent and essential [18].

As noted above, type I CC may present with intrahepatic biliary dilatation secondary to biliary stasis, thus resembling a type IVa CC. Some authors consider that this distinction is critical given the therapeutic implications and the need to include hepatic resection (in the case of type IVa CC) in addition to extrahepatic biliary tree excision [18], whereas the others consider that the need preoperatively distinguishing between type I and IVa CCs is controversial because for both, complete excision of the extrahepatic bile duct and intensive long-term follow-up remains standard of care [11].
