Preoperative Ultrasound Nomogram for Differentiating Polypoid Adenomyoma from Endometrial Polyps

OBJECTIVES: Uterine polypoid adenomyoma (PA) tends to persist, recur, and carry a high risk of malignancy. However, preoperative distinction between PA and endometrial polyp (EP) remains challenging in clinical practice, often leading to suboptimal therapeutic decisions. This study aimed to compare the clinical and ultrasonographic characteristics of PA and EP and to develop a nomogram for accurate preoperative diagnosis. METHODS: We retrospectively identified women with pathologically confirmed PA diagnosed at Peking Union Medical College Hospital between January 2017 and April 2024. Patients with EP hospitalized during the same period and diagnosed postoperatively were randomly selected as the control group. Demographic, clinicopathological, ultrasound, and surgical data were extracted from medical records. Nomogram predictors were identified through univariate and multivariable logistic regression analyses. Model performance was assessed using the area under the receiver operating characteristic curve (AUC), with internal validation via bootstrap resampling (1000 iterations). RESULTS: A total of 52 patients with PA and 52 with EP were included. In the PA group, 32 cases (61.5%) were preoperatively diagnosed as benign by ultrasound, 15 (28.8%) unclassified, and 5 (9.6%) suspected of malignancy. Compared with the EP group, the PA group was significantly older (p < .05) and had higher proportions of postmenopausal status (32.7% versus 7.7%, p < .05) and postmenopausal bleeding (17.3% versus 0%, p < .05). Significant ultrasonographic differences were observed in lesion multiplicity, maximum diameter, morphology, echogenicity, intralesional cysts, blood flow signals, and moderate vascularity (all p < .05). The nomogram incorporated 4 ultrasound parameters: lesion multiplicity, maximum diameter, irregular morphology, and cystic components. The model achieved an AUC of 0.930 (95% CI: 0.884-0.975), outperforming individual parameters (AUC range: 0.606-0.798), with satisfactory calibration (Hosmer-Lemeshow p = .848). CONCLUSION: PA and EP exhibit distinct clinical and ultrasound features. The ultrasound-based nomogram demonstrates discriminative capacity for distinguishing PA from EP, providing a valuable tool for guiding clinical management. However, given the single-center design and limited sample size, further external validation in larger, multi-center prospective studies is warranted to confirm its generalizability and clinical utility.