Dynamic curve type serves as an effective tool for the diagnosis of benign or malignant non-mass enhancements on...

Identifying malignant non-mass enhancement (NME) in contrast-enhanced breast magnetic resonance imaging (MRI) remains a notable diagnostic challenge due to overlapping imaging features between benign and malignant lesions. Although the delayed-phase kinetic patterns are well-established, the diagnostic value of the initial-phase kinetics has not been fully elucidated. The present study aimed to evaluate the dynamic and morphological characteristics of NME lesions, to determine whether incorporating initial-phase kinetics with delayed-phase analysis improves the discrimination between benign and malignant cases. A prospective study was conducted at the Oncology Teaching Hospital (Baghdad, Iraq) from April to December 2022, including patients referred for breast MRI. Only cases with pure NME (without associated mass lesions) were included. A core biopsy was performed for all cases, with excisional biopsy when indicated. Data collection followed the Breast Imaging Reporting and Data System 5th edition criteria. Among 38 enrolled patients (mean age, 45±11.45 years; range, 26-75 years; median, 44 years), 63.2% presented with a breast lump and 26.3% underwent screening. Histopathology confirmed malignancy in 26 cases (68.4%), comprising 12 cases of ductal carcinoma in situ and 14 of invasive ductal carcinoma. Segmental enhancement was the most common malignant pattern [positive predictive value (PPV), 83.3%], followed by regional enhancement (PPV, 64.3%). Benign lesions had slow (58.3%) or medium (41.7%) initial upslopes, whereas 50% of malignant tumors exhibited a rapid initial slope (P=0.001). Persistent delay was observed in 75% of benign cases but in only 26.9% of malignant cases (P=0.005). Integrating the initial upslope with the plateau-phase kinetics increased the PPV for malignancy from 75 to 81.8%. In conclusion, the integration of initial-phase kinetics with traditional delayed-phase and morphological assessment improves the diagnostic accuracy for malignant NME lesions. This multi-parametric approach could potentially serve as a valuable tool to reduce the rate of unnecessary biopsies in the future.