DISTRIBUTION
Focal
A focal NME is typically described as a confined area of enhancement occupying less than 25% of a quadrant.
Fig. 3: Focal NMEs
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.
Fig. 4: Linear NMEs
Fig. 5: Linear Branching NME
Segmental
The triangular/wedge-shaped area for segmental NME is due to the enhancement conforming to a ductal branching system. It suggests the possibility of extensive disease.
Fig. 6: Segmental NMEs
Regional
Contrary its focal counterpart, regional NME involves larger area of the breast (>25%) and does not conform to a single duct system.
Fig. 7: Regional NMEs
Multiple Regions
Multiple regions NME is mostly patchy in appearance and is commonly due to background enhancement.
Fig. 8: Multiple Regions NME
INTERNAL ENHANCEMENT PATTERN
Homogenous
Fig. 9: NMEs with homogenous enhancement pattern
Heterogeneous
Fig. 10: NMEs with heterogeneous enhancement pattern
Clumped
Fig. 11: NMEs with clumped enhancement pattern
Clustered Ring
Fig. 12: NMEs with clustered ring enhancement pattern
SUSPECTED PATHOLOGIC DISCORDANCE
Fig. 13: Suspected pathologic discordance
Fig. 13 demonstrates an example of a woman with suspected pathologic discordance. She is a 42-year-old woman with right breast HPE-proven DCIS. Pre-operative breast MRI showed suspicious segmental left lower region NME with clustered ring enhancement pattern. This NME corresponded to a 6 o’clock lesion seen on second-look ultrasound and core biopsy was performed. Despite the suspicious NME, the pathologic findings were reported as usual ductal hyperplasia (UDH). This woman warranted a repeat biopsy in view of suspected pathologic discordance. After alerting the surgeons on possible discordance, she was planned for right mastectomy as well as hookwire localization and excision of the left 6 o’clock lesion. Unfortunately, she decided to seek for second opinion elsewhere and defaulted.