Prevalence and Size-Based Risk Categorization of Pancreatic Cysts Among Asymptomatic Individuals With Screening MRI.

Importance: Subsets of pancreatic cystic lesions (PCLs) are the only radiographically evident precursors to pancreatic cancer. Guidelines prioritize cyst size and high-risk features to determine the need for resection. However, the true prevalence of PCLs and risk factors for their development in the general population remain unknown, as available data are often biased by imaging performed in symptomatic patients. Objective: To determine prevalence of PCLs in an asymptomatic North American cohort using size-based risk categorization and identify associated demographic factors and exposures. Design, Setting, Participants: This cross-sectional study included asymptomatic individuals who underwent rapid whole-body magnetic resonance imaging using a commercially available 1.5T device for general preventive screening between January 1, 2020, and May 31, 2023. Scans were interpreted by certified radiologists using standardized synoptic reporting templates. Diagnostic free-text reports were analyzed, and positive reports underwent independent additional review. Data were analyzed from February 4, 2024, to March 6, 2025. Exposures: Participant demographic information and lifestyle exposures. Main Outcomes and Measures: Prevalence of PCLs based on size-based risk categorization. Results: Among 21 651 individuals undergoing screening MRI (11 050 [51.0%] male; median age, 51 [IQR, 42-61] years), 1509 (7.0%) had an incidental PCL (776 [51.4%] female), and age- and sex-standardized prevalence was 6.3%. The median age was higher in individuals with PCLs (61 [IQR, 51-69] vs 50 [IQR, 41-60] years). Prevalence increased with age, from 86 of 4223 (2.0%) 39 years or younger to 229 of 5720 (4.0%) aged 40 to 49 years, 390 of 5586 (7.0%) aged 50 to 59 years, 467 of 4049 (11.5%) aged 60 to 65 years, 268 of 1741 (15.4%) aged 70 to 79 years, and 69 of 332 (20.8%) 80 years or older (P < .001). Most cysts (1449 [96.0%]) were less than 2 cm, 1200 (79.5%) were less than 1 cm, and 17 (1.1%) were 3 cm or larger (0.08% of all scans). Independent factors associated with PCLs included being 65 years or older (odds ratio [OR], 3.03; 95% CI, 2.67-3.45), female sex (OR, 1.13; 95% CI, 1.002-1.27), personal history of pancreatitis (OR, 2.65; 95% CI, 1.66-4.08) or pancreatic ductal adenocarcinoma (PDAC) (OR, 20.98; 95% CI 3.70-161.45), family history of PDAC (OR, 1.40; 95% CI, 1.04-1.86), alcohol consumption (OR, 1.15; 95% CI, 1.01-1.31), and Latin American (OR, 1.79; 95% CI, 1.43-2.23) or Middle Eastern (OR, 1.40; 95% CI, 1.03-1.86) ethnicity. Asian ethnicity (OR, 0.79; 95% CI, 0.66-0.95) was associated with lower PCL prevalence. Conclusions and Relevance: In this cross-sectional study of 21 651 individuals, incidental PCLs were common (6.3%) and found in as many as 20.8% of older individuals undergoing whole-body MRI screening, with 1492 PCLs (98.9%) of all PCLs being less than 3 cm.