choledochal cyst – a case report presenting author – dr.k.prasanna post graduate student, rajah...
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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.