Periampullary choledochal diverticula are not choledochal cysts.

BACKGROUND: Choledochal cysts (CC) are rare, congenital anomalies of the biliary tree, associated with the development of biliary malignancies. Small periampullary choledochal diverticula (PCD) are a previously unreported type of biliary anomaly found primarily at ERCP. OBJECTIVE: The aim of this study was to assess whether PCD are congenital or acquired lesions by comparing the clinical presentation, management, and risk of malignancy between patients with PCD and CC. DESIGN: Retrospective analysis of a medical center database. SETTING: Academic tertiary referral center. PATIENTS: Over the study period, data regarding 16 patients with PCD were identified and compared with that of 118 patients with CC. INTERVENTION: Retrospective review of ERCP, surgical pathology, billings, and a diagnostic imaging database from our institution from 1985 to 2009 was done. MAIN OUTCOME MEASUREMENTS: Clinical presentation, investigations, management strategies, complication rates, and long-term outcomes were compared in patients with classic CC and PCD over the same time period. RESULTS: Patients with PCD were less likely to be female (50% vs 81%), older aged (mean 68 vs 28 years), to complain of abdominal pain (88% vs 68%), and were less likely to present with jaundice (0% vs 32%) (P<.05 for all pairs). Patients with PCD also were noted to have lower frequency of anomalous pancreatobiliary junction (0% vs 83%) and biliary neoplasia (0% vs 5%) and more likely to have sphincter of Oddi dysfunction (63% vs 1%). Management of PCD was done with ERCP in 87% of cases and with surgery in 0% of cases, whereas management of CC was done with ERCP in 20% of cases and surgery in 80% of cases (P<.001). Long-term complications at a mean follow-up of 3.7 years after therapy were more common in CC (40% vs 6%, P=.02). LIMITATIONS: Retrospective study. Lack of structured follow up. CONCLUSION: Small, periampullary, choledochal diverticula are a newly reported, likely acquired anomaly of the biliary tract that are frequently associated with sphincter of Oddi dysfunction and may be secondary to biliary hypertension. These acquired lesions should not be classified as CC.