Anatomic Pathology / LOBULAR NEOPLASIA IN BREAST CORE NEEDLE BIOPSY SPECIMENS Lobular Neoplasia in Breast Core Needle Biopsy Specimens Is Not Associated With an Increased Risk of Ductal Carcinoma In Situ or Invasive Carcinoma

Recent reports suggest that the finding of lobular neoplasia (atypical lobular hyperplasia [ALH] or lobular carcinoma in situ [LCIS]) in breast core needle biopsy specimens may be associated with an increased risk of both ductal carcinoma in situ (DCIS) or invasive carcinoma at excision. We reviewed our breast core biopsy material to see if we could confirm this finding. From 4,297 biopsies, 71 cases of lobular neoplasia alone and 35 cases of lobular neoplasia associated with atypical ductal hyperplasia were identified. Biopsy follow-up revealed DCIS or invasive carcinoma in none of 6 cases of ALH, none of 9 cases of LCIS, and DCIS in 1 of 11 cases with both atypical ductal hyperplasia and LCIS. Our results suggest that patients with lobular neoplasia in breast core biopsy specimens are not at increased risk of either DCIS or invasive carcinoma at excision, and patients with this finding and no other clinical or pathologic indications for biopsy can be followed up rather than routinely undergo excision. Recent reports suggest that the finding of lobular neoplasia (atypical lobular hyperplasia [ALH] or lobular carcinoma in situ [LCIS]1) in breast core needle biopsy specimens may be associated with an increased risk of ductal carcinoma in situ (DCIS) or invasive carcinoma at excision.2,3 Such a finding seems unexpected, since lobular neoplasia traditionally has been associated with an increased risk of carcinoma for both breasts rather than an increased risk at that particular site.1,4 If this finding could be confirmed, patients with such a finding would seem to be candidates for routine excision rather than clinical follow-up. As a specific reaction to these reports, during the last year, we have been adding a note to reports for patients with lobular neoplasia revealed by breast core biopsy that recent studies suggest that patients with these findings may be at increased risk and excision may be warranted. However, our experience is that very few of these patients had either DCIS or invasive carcinoma identified in their subsequent excisions. To investigate this, we reviewed the results of all follow-up biopsies in patients with a diagnosis of lobular neoplasia alone or with coexisting atypical ductal hyperplasia (ADH) from a large series of breast core biopsies. Materials and Methods The results of breast core needle biopsy specimens interpreted from August 20, 1996, to August 31, 2001, at Baptist Hospital of Miami, Miami, FL, were reviewed. All biopsy specimens with a diagnosis of lobular neoplasia (either ALH or LCIS) alone or in conjunction with ADH were identified. Criteria for ADH were those identified by others.5 In brief, Am J Clin Pathol 2002;117:797-799 797 © American Society for Clinical Pathology Renshaw et al / LOBULAR NEOPLASIA IN BREAST CORE NEEDLE BIOPSY SPECIMENS these lesions were restricted to intraductal proliferations with some, but not sufficient, features of DCIS. The criteria for lobular neoplasia are those outlined by others.1,4 However, all cases that showed atypical features, such as LCIS with abnormally large cells, were classified for the purposes of this report as ADH and LCIS. All breast core needle biopsy specimens were obtained by the clinicians; more than 95% were performed by the radiology department and consisted almost exclusively of specimens from 11and 14-gauge core needle biopsies performed under ultrasound or stereotactic guidance. All specimens were received fixed and routinely processed. Up to 5 cores were processed in a single block; if more than 5 cores were present, then an additional block was prepared. Each block was entirely sectioned to produce at least 5 slides and 2 levels per slide.6 Statistical analysis was performed using a 2-tailed Fisher exact test.