Clinical characteristics of patients with malignancy and long-term outcomes of surgical treatment of patients with choledochal cyst

There are few reports of postoperative long-term malignant risk or postoperative sequelae after surgery for choledochal cysts (CCs). This study aimed to analyze the clinical characteristics of patients with malignancy and the long-term results of operated CC. The patients who underwent surgical treatments for CC between 2003 and 2020 at Seoul National University Hospital were enrolled. Clinicopathologic factors and pre-/postoperative computed tomography or magnetic resonance imaging were reviewed. Of the 153 patients, Todani classification Ic (36.6%), C-P type (43.8%) anomalous pancreaticobiliary duct union were the most common type respectively. Fourteen patients (9.2%) had biliary tract cancer and a comparison of patients with and without malignancy showed that the diameter of cyst was significantly lower in malignant patients and malignancy was observed to be significantly higher in P-C type. The incidence of long-term complications was 9.8%, and the median time interval was 30 months. The 2 most common complications were cholangitis and stricture (60.0%). There was one case of new cancer near the intrapancreatic remnant bile duct. Of the resected CCs, 9.2% had a combined malignancy on the biliary tracts. Long-term complications such as cholangitis, anastomotic stricture, and new cancers may occur. Therefore, continuous surveillance is required.