Clinical spectrum of adult patients with annular pancreas: Findings from a large single institution cohort

Background and aims: Annular pancreas (AnnP) is a rare congenital abnormality that results from the presence of a complete or partial ring of pancreatic tissue surrounding the descending portion of the duodenum. While the clinical presentation and management of AnnP in neonates and infants has been well described, the complete spectrum of clinical presentation of AP in adults is not very clear. We aimed to describe the clinical spectrum of presentation and management of adult patients with AnnP. Methods: Using the electronic medical record, we identified 198 patients with radiologically and/or surgically confirmed AnnP evaluated at Mayo Clinic between 1995 and 2017. Results: The mean age of the study population at diagnosis was 55.1 (±18.3) years (60% female). 60% of patients did not have symptoms attributable to pancreatic disease at the time of diagnosis and were diagnosed incidentally. Computed tomography (CT) was the most common modality (64%) of diagnosis. Among symptomatic patients, abdominal pain (50%), duodenal obstruction (31%) and acute pancreatitis (16%) were the most common symptoms (non-exclusive). While most patients with duodenal obstruction required surgery, all patients with acute pancreatitis could be managed conservatively in the absence of competing indications for intervention. Conclusion: AnnP may remain asymptomatic well into adulthood and be incidentally detected on abdominal imaging done for other indications. While surgery remains the mainstay of treatment in patients presenting with duodenal obstruction, a majority of these adult symptomatic patients with AnnP, including those with acute pancreatitis require no further treatment.