Objective To investigate the imaging features of pancreatic mucinous cystic tumor (MCN) based on the European evidence‑based guidelines on pancreatic cystic neoplasms and risk factors influencing tumor property.

Methods The retrospective case-control study was con-ducted. The clinicopathological data of 109 pancreatic MCN patients who were admitted to the First Affiliated Hospital of Naval Medical University (Changhai Hospital of Shanghai) from March 2011 to April 2021 were collected. There were 5 males and 104 females, aged (49±15)years. There were 97 cases with benign tumors and 12 cases with malignant tumors. Observation indicators: (1) clinical characteristics of MCN patients with different tumor properties; (2) imaging features of MCN patients with different tumor properties; (3) multivariate analysis of factors affecting evaluating tumor pro-perties of MCN. Measurement data with normal distribution were represented as Mean±SD, and comparison between groups was conducted using the t test. Measurement data with skewed distri-bution were represented as M(range), and comparison between groups was conducted using the Mann‑Whitney U test. Count data were described as absolute numbers, and comparison between groups was performed using the chi-square test or Fisher exact probability. Comparison of ordinal data was analyzed using the non-parameter rank sum test. Statistically significant indicators in clinical and imaging characteristics were included in multivariate analysis. Multivariate analysis was performed by the Logistic regression model forward method.

Results (1) Clinical characteristics of MCN patients with different tumor properties. Gender(male, female), age, body mass index (BMI), cases with clinical symptoms (asymptomatically physical findings, abdominal pain and distension, emaciation, jaundice, pancreatitis, onset diabetes), cases with CA19‑9 (<37 U/mL, ≥37 U/mL), cases with carcinoembryonic antigen (<5.0 μg/L, ≥5.0 μg/L), cases with surgical methods (pancreatoduo-denectomy, pancreatectomy of body and tail, segmental pancreatectomy), cases with tumor location (head of pancreas, tail of pancreas) were 4, 93, (47±14)years, (22±3)kg/m², 56, 35, 2, 1, 11, 5, 89, 8, 96, 1, 2, 90, 5, 4, 93 in the 97 cases with benign tumors, versus 1, 11, (59±17)years, (23±3)kg/m², 4, 4, 1, 0, 3, 2, 5, 7, 7, 5, 0, 12, 0, 0, 12 in the 12 cases with malignant tumors, showing significant differences in age, CA19‑9 and carcinoembryonic antigen (t=‒2.69, χ²=22.57, 26.54, P<0.05) and showing no significant difference in gender, BMI, clinical symptoms, surgical methods and tumor location (P>0.05) between them. (2) Imaging features of MCN patients with different tumor pro-perties. Of the 109 patients with pancreatic MCN, 85 cases underwent computed tomography (CT) plain and contrast‑enhanced scan of pancreas, and 81 cases underwent magnetic resonance imaging (MRI) plain and contrast‑enhanced scan of pancreas. There were 57 cases underwent both CT and MRI plain and contrast‑enhanced scan of pancreas. Cases with tumor location (head of pancreas, tail of pancreas), cases with cyst morphology (circular, lobulated), cases with cyst diameter (<4 cm, ≥4 cm), diameter of cyst, cases with thickening of capsule wall, cases with calcification of capsule wall, cases with enhancing mural nodule of capsule wall, cases with pancreatic duct dilatation were 4, 93, 69, 28, 32, 65, 4.7(range, 3.3‒6.8)cm, 38,20, 4, 13 in the 97 cases with benign tumors, versus 0, 12, 7, 5, 4, 8, 6.8(range, 3.3.‒9.6)cm, 10, 2, 6, 4 in the 12 cases with malignant tumors, showing significant differences in thickening of capsule wall and enhancing mural nodule of capsule wall (χ²=6.75, 21.75, P<0.05) and showing no significant difference in cyst morphology, cyst diameter, diameter of cyst, calcification of capsule wall and pancreatic duct dilatation (P>0.05) between them. (3) Multivariate analysis of factors affecting evaluating tumor properties of pancreatic MCN. Result of multivariate analysis showed that age, carcinoembryonic antigen and mural nodule of capsule wall were independent factors affecting tumor properties of MCN (odds Ratio=1.09, 19.67, 63.57, 95% confidence intervals as 1.01‒1.18, 1.07‒361.49, 4.07‒993.49, P<0.05).

Conclusions Thickening of capsule wall and enhancing mural nodule of capsule wall are imaging features of patients with pancreatic MCN. Age, carcinoembryonic antigen and mural nodule of capsule wall are independent factors affecting tumor properties of pancreatic MCN.