1. To illustrate the various types of non-mass enhancements (NMEs) according to BI-RADS lexicon. 2. To show the role of pathologic correlation in this entity.

According to ACR BI-RADS 5th Edition 2013, non-mass enhancement (NME) is defined as a discrete enhancing area that does not represent a mass. It typically interspersed with non-enhancing fatty or glandular tissue. NMEs can be either benign or malignant. It is most commonly due to fibrocystic change including focal adenosis, hormonal stimulation, inflammatory changes, or intraductal and diffuse cancer. Ductal carcinoma-in-situ (DCIS) have been reported as the most common manifestation of NMEs. Hence, pattern recognition of malignant NMEs are essential. According to ACR BI-RADS, NMEs...

DISTRIBUTION Focal A focal NME is typically described as a confined area of enhancement occupying less than 25% of a quadrant. Linear & Linear Branching Linear NME can be either straight, curved or branching enhancement. Its distribution suggests enhancement within or around a duct. Based on available literatures, “linear branching” distribution have been reported to have a higher positive predictor value for malignancy. This is also seen in our patient with DCIS that presented with linear branching NME. Segmental The triangular/wedge-shaped area for segmental NME...

In summary, NMEs remain a diagnostic challenge and careful characterization is crucial in predicting the malignant causes. Accurate descriptions and classifications are influenced by patient’s hormonal influence, interpretive variability, and reader’s experience. Short-term follow up and biopsy recommendations remain necessary for high-risk patients. It is essential for radiologists to correlate the histopathologic findings with the NME appearance and surgeons should be notified in cases of radio-pathologic discordance. Further research is needed to further stratify and characterize NME patterns in predicting malignancy.

K. S. Loi; Federal Territory of Kuala Lumpur/MY - nothing to disclose W. Y. Chan; Kuala Lumpur/MY - nothing to disclose M. T. Ramli Hamid; Sungai Buloh/MY - nothing to disclose K. Rahmat; Kuala Lumpur/MY - nothing to disclose

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