Contrast Enhanced Mammography (CEM) Enhancing Asymmetry: Single-Center First Case Analysis

Abstract

(1) Purpose: The latest Breast Imaging Reporting and Data System (BI-RADS) lexicon for CEM introduced a new descriptor, enhancing asymmetries (EAs). The purpose of this study was to determine which types of lesions were correlated with EAs. (2) Methods: A total of 3359 CEM exams, executed at AOUC Careggi in Florence, Italy between 2019 and 2021 were retrospectively assessed by two radiologists. For each of the EAs found, the size, the enhancing conspicuity (degree of enhancement relative to background described as low, moderate, or high), whether there was a corresponding finding in the traditional radiology images (US or mammography), the biopsy results when performed including any follow-up exams, and the presence of background parenchymal enhancement (BPE) of the normal breast tissue (minimal, mild, moderate, marked) were described. (3) Results: A total of 64 women were included, 36 of them underwent CEM for a preoperative staging assessment, and 28 for a problem-solving examination. Among the 64 EAs, 19/64 (29.69%) resulted in being category B5 (B5) lesions, 5/64 (7.81%) as category B3 (B3) lesions, and 40/64(62.50%) were negative or benign either after biopsy or second-look exams or follow-up. We assessed that EAs with higher enhancing conspicuity correlated significantly with a higher risk of B5 lesions (p: 0.0071), especially bigger ones (p: 0.0274). Conclusions: EAs can relate both with benign and tumoral lesions, and they need to be assessed as the other CEM descriptors, with re-evaluation of low-energy images and second-look exams, particularly larger EAs with higher enhancing conspicuity.

Keywords: CEM; breast cancer; breast imaging; enhancing asymmetry; second look.

Figure 1

Flowchart of the diagnostic management of CEM enhancing asymmetries—LE: low-energy images; SL: second-look; US: ultrasound; DBT: digital breast tomosynthesis; BI-RADS, Breast Imaging Reporting and Data Systems; CNB: US-guided core needle biopsy (CNB); VABB: tomosynthesis-guided vacuum assisted breast biopsy; MRI: magnetic resonance imaging; VAE: vacuum assisted excision; * Depending on how they have been detected.

Figure 2

(a,b) Graphic representation of the contingency table related to the enhancement conspicuity and the risk of cancer [15].

Figure 3

A 73 year old patient. Contrast-enhanced digital mammography performed as preoperative staging for a B5 lesion in the left breast (arrows). In the early RC in the right breast, there was an enhancing asymmetry in the upper quadrants with high conspicuity only visible in MLO (circle). The EA did not have a clear correspondence in low-energy images. The patient underwent SL-US, which showed a hypoechoic mass of 6.0 mm that was subsequently subjected to CNB (core needle biopsy), which confirmed an invasive tubular carcinoma.

Figure 4

A 62 year old patient. Contrast-enhanced digital mammography performed as preoperative staging for a B5 lesion in the left breast (arrows). In the early RC in the right breast, there was an enhancing asymmetry in the central quadrants with moderate conspicuity only visible in CC (circle), corresponding to an opacity in low-energy images. This opacity subsequently underwent VABB (tomosynthesis-guided vacuum assisted breast biopsy), which showed a benign lesion (fibrocystic breast change).

Figure 5

A 51 year old patient. Contrast-enhanced digital mammography performed as preoperative staging for a B5 lesion in the right breast (arrows). In the early RC in the left breast, there was an enhancing asymmetry in the inner quadrants with moderate conspicuity only visible in CC (circle), corresponding to an opacity in low-energy images. This opacity subsequently underwent VABB (tomosynthesis-guided vacuum assisted breast biopsy), which confirmed an invasive carcinoma.

Figure 6

A 60 year old patient. Contrast-enhanced digital mammography performed as preoperative staging for a B5 lesion in the left breast (arrows). In the early RC in the right breast, there was an enhancing asymmetry in the central quadrants with high conspicuity only visible in CC (circle), corresponding to an architectural distortion in low-energy images. This architectural distortion subsequently underwent VABB (tomosynthesis-guided vacuum assisted breast biopsy), which confirmed a ductal in situ carcinoma.