Pediatric Intraductal Papillary Mucinous Neoplasia

Abstract

Intraductal papillary mucinous neoplasia (IPMN) of the pancreas are premalignant, intraductal, cystic lesions that usually affect men aged 60 to 70. We describe the first reported pediatric case of IPMN. A 14 year-old male presented with recurrent pancreatitis and an amylase of 247 and lipase of 508. Liver function tests were normal. CT scan and ultrasound showed a dilated pancreatic duct, an enlarged pancreatic head, and an atrophied tail. ERCP revealed copious mucin from wide-open, patulous major and minor ampullae. There was pan-dilation of the main pancreatic duct. Pancreatic fluid cytology revealed benign columnar and cuboidal epithelial cells with macrophages and lymphocytes. Shortly thereafter his abdominal pain subsided with normalization of his pancreatic enzymes. A year after, he had a lipase of 8.1 and an amylase of 167. Repeat ERCP showed continued dilation of the major and minor ampullae with a fish-eye appearance and mucinous plugs. Pancreatic endoscopic ultrasound and pancreatoscopy showed a dilated pancreatic duct of 4–5 mm but no masses or cysts. CT scan revealed a 13mm hypodensity in the pancreatic head. He thus underwent a pylorus-saving pancreaticoduodenectomy for IPMN. Intra-operative ultrasound showed a 5 to 8 mm mass in the pancreatic head. Pathology revealed IPMN of borderline malignancy in the pancreatic head involving the main and secondary pancreatic ducts. The parenchyma had multiple cysts lined with tall mucin-producing cells. Epithelial hyperplasia and papillary infoldings with dysplasia were seen and tumor cells stained positive for mucin and cytokeratins 7 and 20. Acinar atrophy, consistent with chronic pancreatitis, was also noted. The patient has done well for over 2 years with no further bouts of pancreatitis. He did develop some mild abdominal discomfort that resolved with pancreatic enzymes and a proton pump inhibitor. Furthermore, levels for serum tumor markers CA 19–9 and carcinoembryonic antigen remain low. This is the first reported pediatric case of IPMN. Although rare, it should be considered whenever the typical fish eye appearance of the ampullae and mucin are noted on ERCP.