Flat epithelial atypia (FEA) is a benign breast lesion found on imaging as calcifications. Several studies examined the risk of FEA upgrading to malignancy after surgical excision. Meta-analyses found an 11.1% upgrade rate to cancer and 17.9% to atypical ductal hyperplasia. A retrospective study of 271 FEA cases found a 15% overall upgrade rate. However, a study of 69 FEA cases biopsied with vacuum-assisted biopsy found no upgrades after obtaining numerous core samples and ensuring complete calcification removal. Another study of 48 similar FEA cases found a low 2% upgrade rate with surveillance including annual mammograms. Therefore, the author's practice will be surveillance of qualifying

1. Does Flat Epithelial
Atypia Always Need
Excision?
Yana Puckett, MD, MBA, MPH, MSc

2. Flat Epithelial Atypia
• Flat epithelial atypia (FEA) is a benign proliferative breast
lesion characterized by 1-5 layers of columnar cell changes
and hyperplasia.
• Precursor to atypical ductal hyperplasia.
• Presents with no symptoms
• Found on imaging as calcifications
• Incidence <2% of all CNB¹
• Upgrade to malignancy 0-42%² (DCIS/Invasive)
• Increased to 18-20% if ADH is present with FEA on original²
CNB.
¹Lavoué, Vincent, et al. "Pure flat epithelial atypia (DIN 1a) on core needle biopsy: study of 60 biopsies with follow-up surgical
excision." Breast cancer research and treatment 125.1 (2011): 121-126.)
²Rudin, Anatoliy V., et al. "Flat epithelial atypia on core biopsy and upgrade to cancer: a systematic review and meta-analysis."
Annals of surgical oncology 24.12 (2017): 3549-3558.

3. Meta-Analysis
• Systematic review and meta-analysis on frequency of
upgrade to cancer or ADH at surgical excision of FEA
• Inclusion criteria: FEA pure or with other high-risk lesions dx
on percutaneous biopsies
• n=1966 of pure FEA on Core Needle Biopsies
• 77% underwent surgical excision
• Upgrade to cancer varied from 0-42%, pooled estimate
11.1%.
• Upgrade to ADH 0 to 60%, pooled estimate 17.9%
• Conclusion: patient management changed for approximately
25% of patients, support surgical excision of FEA when
diagnosed on core biopsy.
Rudin, Anatoliy V., et al. "Flat epithelial atypia on core biopsy and upgrade to cancer: a systematic review and meta-analysis."
Annals of surgical oncology 24.12 (2017): 3549-3558.

4. Retrospective Study on Rate of Upgrade
to Malignancy in FEA
• 271 FEA positive out of 5,555 breast vacuum assisted core
biopsies in France 2003-2010
• 128 pure FEA
• 135 FEA + atypical ductal hyperplasia
• 184 underwent surgical excision and 46 mammographic
surveillance
• 34/184 (15%) were upgraded to malignancy (23 CIS, 7
Invasive, 4 mixed).
• 10/95 pure FEA revealed malignancies (10.5%)
• Final Recommendation: All FEA should undergo excision
Peres, Alexandre, et al. "Rates of upgrade to malignancy for 271 cases of flat epithelial atypia (FEA) diagnosed by breast core biopsy."
Breast cancer research and treatment 133.2 (2012): 659-666.

5. Vacuum Assisted Biopsy
• Retrospective review of FEA with or w/o ADH or ALH
• n=69
• 100% had calcifications as only imaging finding
• Mean of 11 cores (range 6-25) obtained from each lesion.
• Post bxy mammo >90% removal of calcifications in 81% of
cases.
• Pure FEA ⅔ of cases.
• Upgrade rate was 0%.
• Conclusion: Excision may not be necessary for pure FEA as
upgrade was 0%.
McCroskey, Zulfia, et al. "Flat epithelial atypia in directional vacuum-assisted biopsy of breast microcalcifications: surgical excision may
not be necessary." Modern Pathology 31.7 (2018): 1097-1106.

6. Surveillance?
• Retrospective observational study.
• Inclusion Criteria: VAB with no residual calcifications post-
VAB, pure FEA only, radiologic follow-up of at least 12
months.
• Exclusion Criteria: personal history of breast cancer or other
high risk lesion.
• N=48
• Mean f/u 41.5 months.
• 7 to 15 samples were obtained with each VAB.
• Results: only one case of new microcalcifications (2%), ADH
at surgical excision
Schiaffino, Simone, et al. "Flat epithelial atypia: conservative management of patients without residual microcalcifications post-vacuum-
assisted breast biopsy." The British journal of radiology 91.1081 (2018): 20170484.

7. My Practice Will Be...
• Surveillance with 6 mo mammogram, followed by 12 month
mammogram (for new calcifications). If negative, resume q
12 month mammogram surveillance. Only if...
• No discordance on imaging
• All calcifications were confirmed to be removed with VAB
• Biopsy done with VAB with at least 7 samples obtained
• No history of previous breast cancer
• No genetic abnormalities
• No family history of breast cancer
• Able to follow up with mammograms (no social issues)
• Taking age into account