[103] Multifocal Flat Epithelial Atypia: Possible Precursor of Breast Carcinoma

Md Shahrier Amin, Muhannad Hassan, Susan J Robertson, Shahidul Islam. University of Ottawa, Ottawa, ON, Canada

Background: The biological behaviour and management of flat epithelial atypia in breast is not yet established. Whether or not extensive or multifocal FEA is associated with genetic changes that predispose to more advanced breast lesions has not been extensively studied. The aims of this study were: 1. To characterize the radiological presentation, distribution and clinical outcome of FEA; and 2. Evaluate association of FEA distribution with atypical hyperplasia and in situ or invasive carcinoma.
Design: We retrospectively studied 58 breast biopsies and resections at our institution between 2008 and 2010 that contained FEA. Among these 42 were core needle biopsies (CNB), a subsequent resection was done in 25 of these. 16 cases were resection specimens with secondary FEA diagnosis. FEA distribution was assessed semi-quantitatively as: focal (1-2 biopsy fragments or areas per section), multifocal (3 and more fragments or sections but < 50% of total number) and extensive (>50% of fragments or sections).
Results: Radiologic microcalcifications were present in 43 cases. FEA was the sole diagnosis in 15 CNB cases: 2 of these had multifocal FEA, and one case subsequently presented with atypical hyperplasia. FEA was associated with atypical hyperplasia in 15 cases: 8 of these (53%) had mutifocal or extensive FEA, and 3 subsequently presented with DCIS within 1 year. FEA was associated with an in situ or invasive carcinoma in 9 CNB cases: 5 of these (55%) had multifocal FEA. Multifocal FEA was also present in 2 of the 16 resections (12%) for carcinoma.
Conclusions: We are the first to report that multifocal or extensive FEA is more frequently associated with atypical hyperplasia, in situ or invasive carcinoma. Therefore focality of FEA must be mentioned in the diagnosis. Further molecular and genetic studies are required to elucidate whether or not multifocal FEA is a premalignant condition.
Category: Breast

Monday, March 4, 2013 1:00 PM

Poster Session II # 50, Monday Afternoon


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