Choledochoceles: are they choledochal cysts?

The classification of choledochoceles as a type of choledochal cyst stems from the 1959 article by Alonso-Lej and colleagues describing 94 choledochal cysts, only 4 of which were choledochoceles. Even then, Alonso-Lej questioned the propriety of including the choledochocele, stating it was unclear "as to whether or not it originates from the same etiologic factors [as other choledochal cysts]". In 1971, Trout and Longmire also questioned the validity of classifying choledochoceles as choledochal cysts, noting the anatomic position article and variant mucosa of the choledochocele. Wearn and Wiot, in an article titled "Choledochocele: not a form of choledochal cyst", cite the differences in clinical presentation, demographics, and histology as reasons why choledochoceles represent separate entities from choledochal cysts. Over the ensuing decades, numerous investigators have questioned the legitimacy of classifying choledochoceles as choledochal cysts. In our recent series (the only one to our knowledge directly comparing patients with choledochocele and other [type I, II, IV, and V] choledochal cysts), patients with choledochoceles differed from patients with choledochal cysts in their age, gender, presenting symptoms, history of previous cholecystectomy, pancreatobiliary ductal anatomy, management, and most importantly, propensity to developing biliary malignancy. Based on the available cases of choledochoceles found in the literature, combined with the recent series from our institution, we conclude that choledochoceles seem to be distinct entities from choledochal cysts.