[309] Flat Epithelial Atypia on Core Biopsy and Subsequent Surgical Excision: A Five Year Experience

ME Sullivan, CL Schiller. Northwestern University Feinberg School of Medicine, Chicago, IL

Background: Flat epithelial atypia (FEA) of the breast is a problematic and often subtle lesion. Though observational data have shown an association between FEA and synchronous atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS), invasive carcinoma (IC) particularly tubular carcinoma, and lobular neoplasia, a lack of standardized nomenclature, clear objective diagnostic criteria, or certainty about the natural history of FEA have contributed to a lack of standardized recommendations for subsequent surgical excision (SSE) when FEA is identified on core biopsy (CB). In this retrospective review, we report our five-year experience with FEA diagnosed on CB and findings at SSE at an academic medical center (Northwestern University Feinberg School of Medicine).
Design: A search of pathology records revealed 8712 breast CB samples received between 01/03 and 08/08. Of these, FEA (or equivalent diagnosis with variant nomenclature) was among the diagnoses rendered in 812 (9.3%) cases. Cases with IC, DCIS or ADH in the same CB sample were excluded, leaving 56 cases for review. Subsequent breast pathology specimens obtained at our institution, patient age and basic imaging information were obtained from pathology records, and original CB and SSE slides were reviewed.
Results: Of 56 CB cases with FEA, SSE information was available in 42 (75%; 4 mastectomies, 38 lumpectomies). Of these 42 cases, 14 (33%) were shown to have concurrent more significant lesions requiring SSE (ADH, DCIS or IC) as diagnosed by additional biopsy(ies) in the same (N=9) or contralateral (N=5) breast; IC was found at SSE in 3/14 cases and DCIS was found in 3/14 cases. 4 of the 42 (9.5%) cases had atypical lobular hyperplasia (ALH) or lobular carcinoma in situ (LCIS) diagnosed in the same biopsy; none of these had DCIS or IC at SSE. Of the remaining 24 cases (57%), with no more significant lesions than FEA on CB, only one case was upgraded to DCIS (grade 1) at SSE, and none were found to have IC.
Conclusions: FEA is challenging to diagnose and manage. As FEA becomes more frequently encountered on CB (due in part to imaging advances), delineation of guidelines for subsequent management is important. In our 5 year experience, 1/28 (3.6%) cases of FEA diagnosed on CB, with no concurrent more significant lesion, was upgraded to DCIS at SSE. This reinforces the need for diligent search (by pathology and imaging) for synchronous more significant lesions and suggests that close clinical follow-up may be a reasonable management strategy for FEA alone diagnosed on CB.
Category: Breast

Monday, March 9, 2009 11:00 AM

Platform Session: Section B, Monday Morning