CHOLEDOCHAL CYST – A CASE REPORT

PRESENTING AUTHOR – DR.K.PRASANNAPOST GRADUATE STUDENT,

RAJAH MUTHIAH MEDICAL COLLEGE & HOSPITAL (RMMCH),

ANNAMALAI UNIVERSITY, CHIDAMBARAM

CLINICAL HISTORY• 14 year old boy

• Came with complaints of right hypochondrial pain for the past two days

• Associated with fever and vomiting.

• There is no history of trauma.

• On clinical examination there is no evidence of jaundice

• Right hypochondrial tenderness present.

• Clinically diagnosis of liver abscess was made and was referred to radiology

department.

USG ABDOMEN• Ultrasonography of abdomen showed a

9.2 x 6.7 x 5.6 cm well defined cystic

lesion with minimal echogenic layered

debris postero medial to the gall bladder

• No evidence of any colour flow within

the cystic lesion

• communication with the cystic duct

cannot be clearly made out.

• Other abdominal organs appears normal

Cystic lesion

CT ABDOMEN• NECT of abdomen showed there is

focal dilatation of the extra hepatic

biliary tree pushing the gall bladder

anteriorly.

• No evidence of calculi or calcification.

• Gall bladder and other part of biliary

tree appear normal.

• MRCP shows evidence of only focal dilatation of extra hepatic biliary radical with normal appearance of other parts of extra biliary tract.

• Intra hepatic biliary radicals also appears normal.

MRCP

DIAGNOSIS

• Based on the findings a

diagnosis of Type I b

Choledochal cyst is made,

which is focal segmental

dilatation of extra hepatic

biliary duct which was

confirmed post operatively.

DISCUSSION

• Choledochal cysts are congenital segmental aneurysmal

dilatations of any portion of bile ducts, most commonly of the

main portion of the common bile duct.

• Choledochal cysts are rare, with an incidence of 1:1, 00,000-1,

50,000.

• It is 3 to 4 times more common in females and two thirds of the

patients remain asymptomatic before the age of 10.

PATHOPHYSIOLOGY• The origin of these cysts is uncertain. The most likely etiology is bile

duct injury resulting from sequelae of an anomalous junction of the

pancreatic duct and the distal common bile duct (CBD).

• This anomalous junction results in chronic reflux of pancreatic enzymes

into the biliary tree with resultant weakening, scarring and dilatation of

the CBD wall.

• Anomalous junction is found in 10-58% of cases with choledochal cysts.

PATHOPHYSIOLOGY• Normal development of the pancreas.

• The ventral pancreatic anlage is initially

paired, with the left lobe subsequently

disappearing during development. The

ventral pancreatic anlage fuses side by

side with the dorsal anlage.

• (b) Choledochal cysts can occur when the

left ventral anlage persists and disturbs

normal bile duct recanalization.

CLASSIFICATION

• The original classification

of Alonzo-Lej has been

modified by Todani et al

who described five types

of choledochal cysts.

• Type I - most common, accounting for

80-90% (this type can present in utero)

• Ia - dilatation of extrahepatic bile duct

(entire)

• Ib - dilatation of extrahepatic bile duct

(focal segment)

• Ic - dilatation of the common bile duct

portion of extrahepatic bile duct

• Type II - true diverticulum from

extra hepatic bile duct

• Type III - dilatation of extra-

hepatic bile duct within

duodenal wall

(choledochocoele)

• Type IV - next most common

• IVa - cysts involving both intra

and extrahepatic ducts

• IVb - multiple dilatations / cysts

of extra hepatic ducts only

• Type V - multiple dilatations /

cysts of intra hepatic ducts only

(Caroli disease)

• The role of imaging in the evaluation of choledochal cyst is

to

– delineate the anatomy of the cyst,

– determine the relationship of the cyst to the rest of the intra

and extrahepatic biliary tree,

– evaluate associated complications and

– biliary tree abnormalities

• In a choledochal cyst the presence of

– wall thickening,

– mural nodularity RAISES THE POSSIBILITY OF TUMOR

– wall enhancement .

• Direct cholangiographic techniques such as PTC and ERCP are the

most reliable methods to completely evaluate the biliary tree and

the presence of an anomalous junction of the pancreatic duct and

the CBD.

• Once a choledochal cyst is detected at sonography, MR

cholangiography should be performed prior to surgery.

• The large choledochal cysts can be confused with large intra

hepatic cystic lesions such as liver abscess, hydatid cyst on axial CT

imaging alone.

• However the reformatted CT images and MRCP evaluation is

useful in such cases which can easily show the relation of the cyst

to the liver and show communication with other extra hepatic

biliary ducts as seen in this case.

• Complications associated with

choledochal cyst include

– Cholelithiasis,choledocholithiasi

s, cystolithiasis,

– Ascending cholangitis, bile duct

strictures,

– Intrahepatic abscesses, biliary

– Cirrhosis, portal hypertension

– Hepatobiliary malignancy.

Differantial Diagnosis :

• Duodenal diverticulum

• Pancreatic cystic lesions

• Pseudocyst(s)

• Cystic tumours

• Other causes of biliary tree dilatation

• Impacted gallstone

• Cholangiocarcinoma

• Biliary stricture

• References• 1. Savader SJ, Beneati JF, Venbrux AC et al . Choledochal cysts:

classification and cholangiographic appearance. AJR 1991;156:327-331.• 2. Montana MA, Rohrmann CA. Cholangiocarcinoma in choledochal cyst:

preoperative diagnosis. AJR 1986;147:516-517. [PUBMED]• 3. Babbit DP. Congenital choledochal cyst: new etiological concept based

on anomalous relationships of common bile duct and pancreatic bulb. Ann Radiol (Paris) 1969;12:231-240.

• 4. Todani T, Watanabe Y, Narusue M et al . Congenital bile duct cysts: classification, operative procedure and review of thirty seven cases including cancer arising from choledochal cyst. Am J Surg 1977;134:263-269.