A total of 20 patients aged between 40 and 60 years were included in this study. Among the 20 non-mass enhancement (NME) breast lesions analyzed, 10 were malignant (7 cases of ductal carcinoma in situ [DCIS] and 3 cases of invasive lobular carcinoma), while 10 were benign, including fibrocystic changes and papillomas [1][4].

MRI assessment revealed that segmental enhancement patterns were observed in 30% of cases, with a malignancy rate of 42%, whereas regional enhancement was present in 50% of cases, associated with a lower malignancy rate of 24%. These findings align with previous studies indicating that segmental enhancement is more frequently associated with malignancy, particularly DCIS [4].

Dynamic contrast-enhanced (DCE) MRI analysis showed that the wash-out type kinetic curve (type III) was identified in 60% of malignant cases, significantly higher than in benign cases (20%, P=0.02). In contrast, the persistent enhancement curve (type I) was more common in benign lesions (40%) compared to malignant ones (10%). The sensitivity and specificity of the kinetic curve model for predicting malignant NME lesions were 94.6% and 31.0%, respectively [5] [6].

Diffusion-weighted imaging (DWI) analysis demonstrated that 80% of malignant lesions showed diffusion restriction, compared to 70% of benign lesions, though this difference was not statistically significant (P=0.21). However, apparent diffusion coefficient (ADC) values were significantly lower in malignant lesions (0.91 ± 0.14 ×10⁻³ mm²/s) compared to benign lesions (1.40 ± 0.19 ×10⁻³ mm²/s) (P<0.05). An ADC threshold of ≤1.3 ×10⁻³ mm²/s demonstrated a sensitivity of 85.2% and specificity of 47.5% for malignancy prediction [4] [5].

Histopathological evaluation confirmed that DCIS accounted for 70% of malignant cases, while invasive lobular carcinoma represented 30%. A significant correlation was observed between NME and mammographic microcalcifications, reinforcing MRI’s superior sensitivity (92.3%) for detecting NME compared to mammography (30.8%), particularly in cases without visible calcifications. These findings highlight MRI’s critical role in identifying high-risk lesions and guiding biopsy [6].

Further analysis of DCIS versus invasive carcinoma revealed that 100% of invasive lobular carcinoma cases exhibited diffusion restriction, whereas 50% of DCIS cases showed similar findings. The mean ADC value of invasive carcinoma (0.93 ×10⁻³ mm²/s) was significantly lower than that of DCIS (1.15 ×10⁻³ mm²/s) (P<0.05), consistent with previous studies emphasizing ADC differences between in situ and invasive malignancies [3][6].

These results reinforce the importance of MRI in characterizing NME, particularly in differentiating benign from malignant lesions. Features such as segmental distribution, clustered-ring enhancement, wash-out kinetic curve, and low ADC values significantly increase the likelihood of malignancy, underscoring the need for a comprehensive multimodal diagnostic approach incorporating imaging and histopathology [Figure 4,5,6,7,8] [2].