ABSTRACT
Incomplete resection of choledochal cysts (CCs) that extend deep into the pancreas can lead to protein plug or stone formation, pancreatitis, and cholangiocarcinoma. We encountered two cases of choledocholithiasis in remnant intrapancreatic CCs, in which the patients exhibited symptoms after 3 and 21 years of cyst excision. A 21-year-old woman who had undergone excision of a CC, as a neonate, presented with epigastric pain. Abdominal computed tomography (CT) revealed stones inside the remnant pancreatic cyst, which were removed by endoscopic retrograde cholangiopancreatography (ERCP), and her symptoms improved. A 33-year-old woman, who underwent cyst excision 3 years ago, presented with pancreatitis. Abdominal CT showed a radiolucent plug inside the remnant pancreatic cyst. The soft, whitish plug was removed by ERCP, and the pancreatitis improved. These cases indicate that plugs and stones in CCs have the same pathogenetic mechanism, and their form depends on the time since the incomplete excision surgery.