According to the Todani modification of the Alonso-Lej classification, which type of choledochal cyst is the MOST common?

• A Type II, true diverticulum arising from the common bile duct
• B Type I, fusiform or saccular dilatation of the extrahepatic bile duct ✓
• C Type III, choledochocele confined to the duodenal wall
• D Type IVa, multiple intrahepatic and extrahepatic cysts

Explanation

Todani type I cysts, fusiform or cystic dilatation of the common bile duct with normal intrahepatic ducts, account for roughly 80 to 90% of choledochal cysts and are by far the most common. Type II diverticula are rare, type III choledochocele accounts for under 5%, and type IVa involves both systems but is less frequent than type I. An anomalous pancreaticobiliary junction with a long common channel is the accepted pathogenetic mechanism.

Reference: Grainger and Allison's Diagnostic Radiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.