[299] Pathologic Findings in MRI-Directed Needle Core Biopsies of the Breast in Patients with Newly Diagnosed Breast Cancer

KP Siziopikou, MA Cobleigh, G Solmos, P Gattuso, P Jokich. Rush University Medical Center, Chicago, IL

Background: For patients with newly diagnosed breast carcinoma, evaluation of the extent of the disease in the breast is of paramount importance in planning appropriate surgical therapy. Magnetic resonance imaging (MRI) plays an ever increasing role in the evaluation of additional areas in the affected breast deemed suspicious by MRI but indeterminate by other radiologic modalities. In this study we evaluated the pathologic findings in MRI-directed needle core biopsies of the breast directed against other suspicious areas in the affected breast of patients with a new diagnosis of breast carcinoma.
Design: Our study population consisted of 44 MRI-directed needle core biopsies of the breast performed on 40 patients with newly diagnosed breast carcinoma at Rush University Medical Center in Chicago (May 2007-July 2008). The histologic findings of these biopsies were reviewed and recorded.
Results: Overall 9/44 (20.4%) of our MRI-directed breast biopsies were malignant, 29/44 (66%) were benign and 6/44 (13.6%) showed atypia. Of the 9 malignant cases, 4 were infiltrating ductal carcinomas with tubular features, 2 infiltrating lobular carcinomas and 3 were ductal carcinoma in situ lesions. Of the 6 atypical cases, 2 were atypical ductal hyperplasia (ADH), 2 atypical lobular hyperplasia (ALH) and 2 showed areas of columnar cell hyperplasia with atypia. Of interest, more than one third of our benign cases (11/29, 38%) consisted of a specific complex multicystic lesion lined by apocrine metaplastic epithelium.
Conclusions: 1. MRI-directed needle core biopsies of separate lesions in the affected breast of patients with newly diagnosed breast carcinoma show additional foci of malignancy in 20% of the cases. 2. A high percentage (66%) of these additional suspicious areas are benign by histologic examination. More specifically, MRI-directed needle core biopsies seem to target a specific complex multicystic lesion lined by apocrine metaplastic epithelium, in over one third of the cases. These findings suggest that MRI-directed core biopsies result in important change of surgical management in a significant number of cases. In addition, MRI-directed needle core biopsies often target benign lesions with specific histopathologic characteristics.
Category: Breast

Wednesday, March 11, 2009 1:00 PM

Poster Session VI # 28, Wednesday Afternoon