A novel distinguishing system for the diagnosis of malignant pancreatic cystic neoplasm

Abstract

Purpose: To explore a simple and reliable non-invasive distinguishing system for the pre-operative evaluation of malignancy in pancreatic cystic neoplasm (PCN).

Methods: This study first enrolled an observation cohort of 102 consecutive PCN patients. Demographic information, results of laboratory examinations, and computed tomography (CT) presentations were recorded and analyzed to achieve a distinguishing model/system for malignancy. A group of 21 patients was then included to validate the model/system prospectively.

Results: Based on the 11 malignancy-related features identified by univariate analysis, a distinguishing model for malignancy in PCN was established by multivariate analysis: PCN malignant score=2.967 × elevated fasting blood glucose (FBG) (≥6.16 mmol/L) ± 4.496 × asymmetrically thickened wall (or mural nodules ≥ 4 mm) ± 1.679 × septum thickening (≥2 mm)-5.134. With the optimal cut-off value selected as -2.8 in reference to the Youden index, the proposed system for malignant PCN was established: septum thickening (>2 mm), asymmetrically thickened wall (or mural nodules>4 mm), or elevated FBG (>6.16 mmol/L, accompanying commonly known malignant signs), the presence of at least one of these 3 features indicated malignancy in PCN. The accuracy, sensitivity and specificity of this system were 81.4%, 95.8% and 76.9%, respectively. MRI was performed on 32 patients, making correct prediction of malignancy explicitly in only 68.8% (22/32). The subsequent prospective validation study showed that the proposed distinguishing system had a predictive accuracy of 85.7% (18/21). Moreover, a higher model score, or aggregation of the features in the proposed system, indicated a higher grade of malignancy (carcinoma) in PCN.

Conclusion: Elevated FBG (>6.16 mmol/L), asymmetrically thickened wall (or mural nodules>4 mm) and septum thickening (>2 mm) are of great value in differentiating the malignancy in PCN. The developed distinguishing system is reliable in the diagnosis of malignant PCN.

Keywords: Blood glucose; Magnetic resonance imaging; Pancreatic cyst; Pancreatic neoplasm; Tomography; X-ray computed.