Diagnostic Value and Management Strategy of Nomogram for PND Based on Clinical Characteristics and CEUS

Objectives The aims of this study was to develop and validate a nomogram utilizing patient clinical information, conventional ultrasound, and contrast-enhanced ultrasound (CEUS) to predict the risk of malignant lesions causing pathologic nipple discharge (PND). Additionally, the study aimed to compare the diagnostic performances of different methods to stratify and clinically manage patients with PND. Materials and Methods A total of 593 patients were retrospectively collected from January 2021 to February 2025, resulting in the inclusion of 334 female patients (mean age 55.0 years; age range 21 to 90 years) who met the inclusion criteria. The patients were divided into development, internal validation, and external validation groups. Clinical information, routine ultrasound, and ultrasonographic characteristics were analyzed using univariate logistic regression, multivariate logistic regression, and Least Absolute Shrinkage and Selection Operator (LASSO) regression to develop a risk prediction nomogram. The diagnostic performances of the nomogram, conventional ultrasound BI-RADS, and ultrasonography 5 points related to the BI-RADS category (5 points modified BI-RADS) were compared. Results Predictive variables for the nomogram included age, the maximum diameter of the lesion, calcifications, boundary with duct, enhancement area, and enhancement margin. Nomogram showed superior performance compared to other diagnostic methods. In the internal validation group, there was no significant difference in diagnostic accuracy between the nomogram and 5-point modified BI-RADS. However, in all other groups, the nomogram outperformed the conventional ultrasound BI-RADS and 5-point modified BI-RADS. Conclusion Constructing a nomogram that combines ultrasound, CEUS, and clinical information can improve the diagnostic efficiency of PND. The nomogram shows optimal diagnostic performance and helps avoid unnecessary biopsies of most benign lesions.