Metachronous occurrence of main-duct intraductal papillary mucinous neoplasm (IPMN) and adenocarcinoma in a chronic pancreatitis patient: A case report

RATIONALE: Chronic pancreatitis (CP) is a risk factor for developing pancreatic ductal adenocarcinoma (PDAC). In addition, a patient with partial pancreatectomy for intraductal papillary mucinous neoplasm (IPMN) can also lead to PDAC. In contrast, IPMN is a distinct disease entity, independent of CP, and there have been few reports that CP is the cause of IPMN. To the best of our knowledge, this is the first clinical case report of the metachronous occurrence of main-duct IPMN and PDAC with a 9 and half-year interval in a patient with chronic alcoholic pancreatitis. PATIENT CONCERNS: A 50-year-old man with a long medical history of recurrent alcoholic pancreatitis and hepatitis over a decade was diagnosed with another episode of acute pancreatitis based on laboratory findings and clinical symptoms. The patient underwent pylorus-preserving pancreaticoduodenectomy (PPPD) for a small nodular lesion in the main duct of the pancreatic head and was diagnosed with main-duct IPMN low-grade dysplasia and associated fibrosing CP. Nine and a half years later, a 59-year-old man lost 7 kg over 3 months and was diagnosed with new-onset diabetes mellitus. DIAGNOSIS: The patient was diagnosed with metachronous, well-differentiated PDAC with concomitant CP. INTERVENTIONS: The patient underwent radical antegrade modular pancreatosplenectomy (RAMPS) for a small nodular mass in the remnant pancreas. OUTCOMES: The patient was healthy for 44 months without evidence of tumor recurrence during clinical follow-up examinations including laboratory findings, tumor marker, and imaging studies. LESSONS: Early diagnosis of metachronous pancreatic neoplasia in a patient with chronic pancreatitis could be made by correlating newly developed clinical symptoms and signs with careful radiological examinations.