[300] Evaluation of 2358 Breast Needle Biopsy Cases: Patients with Pure Atypical Flat Lesions Could Be Spared Surgical Excision

Rin Yamaguchi, Maki Tanaka, Jun Akiba, Yoshiki Naito, Hirohisa Yano. Kurume University School of Medicine, Kurume, Japan; Social Insurance Kurume Daiichi Hospital, Kurume, Japan

Background: The management of atypical flat lesions and other atypical ductal/lobular hyperplasia remains under discussion and the terminology used is confusing. In the present study, we focused on atypical flat lesions with other atypical lesions and low-grade ductal carcinoma in situ (DCIS).
Design: We examined the subsequent surgical results and follow-up data on borderline lesions and low-grade DCISs for 2358 needle biopsy cases.
Results: There were 17 cases (0.72%) with pure flat epithelial atypia (FEA), 44 (1.87%) with pure atypical ductal hyperplasia (ADH) and three (0.13%) with pure atypical lobular hyperplasia (ALH). In addition, there were 18 cases (0.76%) with ADH + FEA, three (0.13%) with ALH + FEA and one (0.04%) with ALH + FEA + ADH. The total number of cases with borderline lesions was 86 (3.65%). Subsequent surgical excision revealed the following incidences of malignancy: pure FEA (1/8) vs. pure ADH (17/31) (p = 0.0489); pure FEA (1/8) vs. FEA + ADH (7/10) (p = 0.0248); pure FEA (1/8) vs. pure FEA + ALH (2/3) (p = 0.152); pure ADH (17/31) vs. FEA + ADH (7/10) (p = 0.265). Among the 2358 cases, 703 had cancer and 155 had DCIS. Pure clinging carcinoma, monomorphous type (; pure FEA) was not seen in the 78 cases (50.3%) with low-grade DCIS. None of the cases of low-grade DCIS recurred during a follow-up period of 925.6 ± 429.9 days.
Conclusions: The pure type of clinging (monomorphous) DCIS (pure FEA) was rarely seen, especially in surgical specimens. After diagnosis of pure FEA using needle biopsy, follow-up findings including imaging data indicated that its appearance did not change during the follow-up period. Thus, we concluded that patients with pure FEA could be spared surgical excision, and that FEA is a more appropriate term than clinging (monomorphous) carcinoma or flat type DCIS.
Category: Breast

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 18, Tuesday Morning

 

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