NON-MASS ENHANCEMENT CHARACTERISTICS IN DYNAMIC BREAST MRI AND THE RELATIONSHIP BETWEEN MASS-ASSOCIATED NON-MASS ENHANCEMENT AND MALIGNANCY

Hülya Çetin TUNÇEZ, Mehdi CAN, Zehra Hilal ADIBELLI, Demet Kocatepe ÇAVDAR

European Journal of Therapeutics - 2026;32(3):325-334

Department of Radiology, İzmir City Hospital, İzmir, Türkiye

 

Objective: This study aimed to explore the association between dynamic breast MRI features of non-mass enhancement (NME) and clinical as well as histopathological outcomes, and to compare the imaging characteristics of mass-associated NME with their pathological correlates. Methods: Breast MRI examinations performed at our institution between January 2019 and October 2023 were retrospectively reviewed. Patients displaying NME with either histopathological confirmation or a minimum of 24 months of MRI follow-up were included. Exclusion criteria comprised prior neoadjuvant chemotherapy, lack of pathology or adequate follow-up, and pregnancy or lactation. NME findings were assessed using the 5th edition BI-RADS MRI lexicon, and lesions adjacent to a mass were categorized separately. Results: Seventy-seven women met the inclusion criteria; 44 (57.1%) NMEs were malignant and 33 (42.9%) were benign. Patients with malignant NME were significantly older. Malignant lesions more frequently demonstrated plateau or washout enhancement kinetics, whereas persistent enhancement predominated in benign cases. Diffusion restriction was substantially more common in malignant lesions, which also showed significantly lower ADC values. More than half of the NMEs (54.5%) were mass-associated, and the vast majority of these (83.3%) were malignant. Tumor size and histopathological subtype did not significantly differ between malignant mass-associated and non-mass-associated NME. Conclusion: Advanced age, segmental distribution, clumped or clustered-ring enhancement patterns, diffusion restriction, and reduced ADC values were strongly associated with malignant NME. NME contiguous with a mass showed markedly elevated malignancy rates and should be carefully considered during preoperative planning.