[171] Significance of Lobular Carcinoma In Situ (LCIS), Nuclear Grade 2 on Breast Core Needle Biopsies

F Gao, G Carter, M Chivukula. Magee Women's Hospital of UPMC, Pittsburgh, PA

Background: LCIS is regarded as a risk factor for development of subsequent invasive carcinoma (IC). It's still unclear at this time, the role of LCIS as a precursor lesion. Though the literature on LCIS is emerging, there are many questions still unanswered. The current treatment of LCIS includes a close follow-up and consideration for tamoxifen treatment for reduction of cancer risk long term in these patients. Many variants of LCIS have been described based on pathologic features such as nuclear grade, pleomorphism and necrosis but very little is known about the biology of these variants. The proposed three tier grading system classifying LCIS has not been validated nor endorsed across the laboratories. We found a significant upstaging of pure pleomorphic LCIS (LCIS with nuclear grade 3) upto 25% in CNB (chivukula et al). The aim of our study was to address the importance of this ambiguous nuclear grade 2 (LCIS-NG 2) diagnosed on CNB along with clinicopathologic follow-up.
Design: The co-path pathology report archives using natural language search in the Department of Pathology were searched for the period of 2006-2008 to include the surgical pathology reports for consecutive breast core biopsies during a 2-year period. Cases in which pure LCIS, nuclear grade 2 in the diagnosis were selected and reviewed. All cases with associated ductal carcinoma in situ (DCIS) or IC (ductal or lobular) were excluded. The clinical, pathologic and radiologic follow-up data was obtained.
Results: Total number of CNB performed from 2006-2008 was 8054. Based on the strict criteria, 27 cases of pure LCIS, nuclear grade 2 were selected. Radiologic biopsies performed were in majority stereo-tactic guided (78% (21/27), remainder were MRI and ultrasound guided. Though all stereotactic biopsies were performed for calcifications (ca++), 93% (25/27) showed presence of Ca++. In the follow-up resections, DCIS or IC was seen in 11% (3/27), residual LCIS seen in 48% (13/27) cases and other high risk lesions such as atypical ductal hyperplasia were seen in 37% (10/27) of cases. No follow-up was available in 19% (5/27) cases.
Conclusions: 1. A great majority of these cases w/ LCIS NG 2 are associated with microcalcifications. 2. The upstaging to a more significant lesion in comparison to pleomorphic LCIS is lower (48% versus 11%), 3. Follow-up excision is recommended in patients with LCIS-NG 2 due to residual LCIS, and associated high risk lesions resulting in upstaging.
Category: Breast

Wednesday, March 11, 2009 9:30 AM

Poster Session V # 20, Wednesday Morning