[295] Upgrade Rates of Lobular Neoplasia on Core Needle Biopsy: Should Atypical Lobular Hyperplasia Be Routinely Excised?

MH Rendi, SM Dintzis, PR Eby, KE Calhoun, KH Allison. Univ. of Washington, Seattle

Background: There is debate as to the best management strategy when lobular carcinoma in situ (LCIS) and/or atypical lobular hyperplasia (ALH) are identified on core needle biopsy (CNB). While some institutions consistently recommend excision due to the risk of upgrade to ductal carcinoma in situ (DCIS) or invasive carcinoma, others consider each on a case by case basis. Our institution has been routinely recommending excisional biopsy following diagnosis of ALH and LCIS on CNB since 2003. Consequently, we have a significant collection of cases with minimal selection bias allowing study of the frequency of upgrade rates in this group.
Design: All cases of lobular neoplasia (ALH and LCIS) diagnosed on CNB were identified from our pathology database since 2003, when surgical excision was first recommended. The imaging modality which prompted the biopsy and the pathologic findings on surgical follow-up were recorded. Upgrade rates to invasive carcinoma or DCIS for both ALH and LCIS were calculated. CNB cases with atypical ductal hyperplasia (ADH), DCIS, invasive carcinoma, or pleomorphic LCIS were excluded from analysis.
Results: 151 cases of lobular neoplasia (ALH, n=91 and LCIS, n=60) diagnosed from 2003-2009 on CNB were identified. Of these, 96 cases had lobular neoplasia without associated ADH or higher grade lesion on CNB, and 80 (83%) had available surgical follow-up. Overall, there was an upgrade rate of 10% to a more significant pathologic lesion (7.5% to DCIS and 2.5% to invasive lobular carcinoma). Of the 45 cases of pure ALH, there were no upgrades to DCIS. Only 1 ALH case upgraded to invasive lobular carcinoma (2.2%) and that lesion was associated with a mass on imaging. None of the cases of ALH biopsied for findings unrelated to a mass upgraded. LCIS on CNB (n=35) had a higher upgrade rate of 20%, with 17.1% upgrading to DCIS (n=6) and 2.8% upgrading to invasive lobular carcinoma (n=1). Interestingly, unlike the ALH case that upgraded, none of the upgraded LCIS lesions were associated with a mass on imaging.
Conclusions: In our experience, ALH diagnosed on CNB for non-mass related findings did not upgrade to DCIS or invasive carcinoma at surgical biopsy, suggesting routine excision may not be necessary in this setting. LCIS, however, had an upgrade rate similar to those reported for ADH, and excisional biopsy should continue to be offered to rule out an associated higher grade lesion. Finally, these findings suggest that ALH and LCIS on CNB carry inherently different risks of having associated invasive carcinoma.
Category: Breast

Monday, March 22, 2010 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 31, Monday Morning


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