Intraductal US aids detection of carcinoma in situ in a patient with a choledochal cyst

The Curious Case of the Choledochal Cyst—Revisiting the Todani Classification: Case Report and Review of the Literature

Choledochal cysts (CCs) are rare occurrences presenting as dilatations of biliary structures, which can present as single or multiple dilatations and can appear as both intra- and extrahepatic anomalies. The most widespread classification of CCs is the Todani classification, but there have been numerous reports of cysts that do not fall into any of the types described. We present such a case—a male patient 36 years of age who underwent preoperative CT, MRCP, and ERCP, which mistakenly indicated a type II Todani CC, and intraoperatively was found to be located at the confluence of the hepatic ducts and encompassed the origin of the common bile duct. Complete resection of the cyst and the proximal segment of the common bile duct was performed, and reconstruction was carried out by Roux-en-Y double-tutorized hepaticojejunostomy. Considering the risk of malignant transformation, the frequent preoperative misdiagnosis, as well as the technically challenging surgery required in such cases, we advocate for a revision of the classification and raise awareness of the need for guidelines regarding the proper short-term and long-term management of this disease to ensure adequate quality of life and disease-free survival for patients.