Adrienne Rebecca Newburg MD, Presenter: Nothing to Disclose

Chloe Muy-Chou Chhor MD, Abstract Co-Author: Nothing to Disclose

Leng Leng Young Lin BA, MD, Abstract Co-Author: Nothing to Disclose

Jennifer Gillman, Abstract Co-Author: Nothing to Disclose

Jin Ah Kim MD, Abstract Co-Author: Nothing to Disclose

Hildegard B. Toth MD, Abstract Co-Author: Nothing to Disclose

Linda Moy MD, Abstract Co-Author: Nothing to Disclose

Differentiation of physiologic versus pathologic enhancement on breast MRI can present a diagnostic challenge. Background parenchymal enhancement (BPE) was recently incorporated into the 5th edition BIRADS lexicon, defined as the volume and intensity of fibroglandular tissue enhancement. However, physiologic enhancement may be non-uniform or asymmetric, and pathologic NME can be diffuse. We have observed that NME described as “diffuse” did not yield malignancy at follow-up or biopsy. Therefore, the purpose of the study was to determine frequency of subsequent malignancy on follow-up for NME described as diffuse.

An IRB-approved, retrospective review of 5,837 consecutive breast MRIs performed from 2005-2011 identified 928 NME lesions for which follow-up or biopsy was recommended. We queried our database for the following terms: “diffuse NME” “scattered” “patchy areas” “bilateral stippled enhancement” or “likely benign fibrocystic change” in the MRI report impression. For purposes of this study these terms were categorized as diffuse. We identified 94/928(10%) cases which were evaluated by 2 fellowship-trained breast radiologists using 5th edition BIRADS lexicon. We sought to determine if enhancement pattern was benign and could be assigned one of 4 BPE categories. Final BIRADS assessment, BPE category and follow-up exams were recorded.

Mean age of patients with NME described as diffuse was 44 years, range 22-73. Of the 94 NME described as diffuse, 21/94(22%) had no further breast imaging at our institution. Of the remaining 73, 4(5%) underwent biopsy with benign results. No subsequent cancers were identified for 73/73 (100%) of diffuse NME at follow-up (mean 2.6 yrs, range 0.1 to 4.8). 1/73 (1.4%) patients developed an interval malignancy after 2.5 yrs of follow-up, which was biopsy-proven DCIS manifesting as a new linear focal area of NME distinct from the background enhancement. BPE categories for the 73 cases were 7/73(10%) minimal, 32/73(44%) mild, 29/73(40%) moderate, 5/73(7%) marked.

Diffuse NME had a 0% PPV for malignancy.

Diffuse breast tissue enhancement may be classified as BPE, with no additional follow-up or biopsy required. The introduction of the term BPE into the BI-RADS lexicon is useful.

Newburg, A, Chhor, C, Young Lin, L, Gillman, J, Kim, J, Toth, H, Moy, L, Diffuse Non-mass Enhancement (NME) May Safely Be Categorized as Background Parenchymal Enhancement.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14019073.html