Background Parenchymal Enhancement in Patients with Invasive Lobular Carcinoma- Comparison with Healthy Controls and Analysis of Preoperative MRI Results

Yael Rapson 1,2 Moran Manor 1,2 Shlomo Gavrieli 1,2 Matan Cohen 3 Itai Gadiel 1,2 Eli Atar 1,2 Ahuva Grubstein 1,2
1Department of Imaging, Rabin Medical Center - Beilinson Hospital, Israel
2Sackler Faculty of Medicine, Tel Aviv University, Israel
3Jerusalem District, Clalit Health Services

PURPOSE: High degrees of background parenchymal enhancement (BPE) may mask or mimic pathologic processes, thus lowering the test sensitivity and specificity. The relative tendency of lobular carcinoma to be multifocal, has the potential of altering the reader’s perception of additional findings in the MRI examination. The first aim of our study was to assess the level of BPE in women diagnosed with invasive lobular carcinoma (ILC). The second aim, was to assess the effect of BPE level on the recommendations regarding further biopsies or follow up in these patients.

MATERIALS AND METHODS: Preoperative breast MRIs for women with ILC, between 2010 and 2016, were collected. The control group included MRI examinations of women without active breast malignancy and without known BRCA carrier status (as BRCA carriers were shown to have a lower BPE in a previous study we conducted). In addition to BPE, examination results were collected (including addtional findings and recommendations) biopsy results, and follow-up MRI results.

RESULTS: The ILC group included 62 patients, with an average age of 61 years. The control group included 115 patients with an average age of 51 years. In the ILC group 44% had high BPE (BPE 3 and 4) in comparison with 36% in the control group.

The biopsy recommendation rate in the study group was 63%, in the control group the rate of BIRADS-4 was 13%.

The PPV 2 of the study group was 46% (18 positive results of 39 biopsy recommendations).

The mastectomy rate in the study group was 26% (16 patients of 62).

CONCLUSION: Although the ILC patients were older, they had higher BPE. There were high rates of biopsy recommendation (63%) and a high PPV (46%).

Even though additional disease was found in the preoperative MRI, there was not a higher rate of mastectomies, in comparison with the literature.

Yael Rapson
Yael Rapson