Choledochal cysts are congenital conditions involving cyst

Cyst

A cyst is a closed sac, having a distinct membrane and division on the nearby tissue. It may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst could go away on its own or may have to be removed through surgery.- Locations :* Acne...

ic dilatation of bile ducts. They are uncommon in western countries but not as rare in East Asian nations like Japan and China.

Signs and symtoms

Most of them present in 1st year of life; adult presentation is rare and usually at this stage is associated with complication . Classic triad of intermittent abdominal pain, jaundice

Jaundice

Jaundice is a yellowish pigmentation of the skin, the conjunctival membranes over the sclerae , and other mucous membranes caused by hyperbilirubinemia . This hyperbilirubinemia subsequently causes increased levels of bilirubin in the extracellular fluid...

, and a right upper quadrant abdominal mass

Abdominal mass

An abdominal mass is any localized enlargement or swelling in the human abdomen. Depending on its location, the abdominal mass may be caused by an enlarged liver , enlarged spleen , protruding kidney, a pancreatic mass, a retroperitoneal mass , an abdominal aortic aneurysm, or various tumours, such...

is found only in minority of patients.

Types

They were classified into 5 types by Todani in 1977.

Classification was based on site of the cyst or dilatation. Type I to IV has been subtyped.

• Type I: Most common variety (80-90%) involving saccular or fusiform dilatation of a portion or entire common bile duct
  Common bile duct
  The common bile duct is a tube-like anatomic structure in the human gastrointestinal tract. It is formed by the union of the common hepatic duct and the cystic duct . It is later joined by the pancreatic duct to form the ampulla of Vater...
  
   (CBD) with normal intrahepatic duct.
• Type II: Isolated diverticulum protruding from the CBD.
• Type III or Choledochocele: Arise from dilatation of duodenal portion of CBD or where pancreatic duct
  Pancreatic duct
  The pancreatic duct, or duct of Wirsung , is a duct joining the pancreas to the common bile duct to supply pancreatic juices which aid in digestion provided by the "exocrine pancreas"...
  
   meets.
• Type IVa: Characterized by multiple dilatations of the intrahepatic and extrahepatic biliary tree
  Biliary tree
  The biliary tract is the common anatomical term for the path by which bile is secreted by the liver then transported to the first part of the small intestine, also known as the duodenum...
  
  .
• Type IVb: Multiple dilatations involving only the extrahepatic bile ducts.
• Type V or Caroli's disease: Cystic dilatation of intra hepatic biliary ducts.

Treatment

Choledochal cysts are treated by surgical excision of the cyst with the formation of a roux-en-Y

Roux-en-Y

Roux-en-Y may refer to:*A type of gastric bypass operation*Roux-en-Y anastomosis...

 anastomosis to the biliary duct.
Future complications include cholangitis and a 2% risk of malignancy, which may develop in any part of the biliary tree.