[186] Atypical Apocrine Adenosis of the Breast on Core Biopsy

Shabnam Jaffer, Sarah Frost, Anupma Nayak, Chandandeep Nagi, Ira J Bleiweiss. Mount Sinai Medical Center, New York, NY

Background: Atypical apocrine adenosis (AAA) of the breast is defined by sclerosing adenosis infused by atypical apocrine epithelium (characterized by at least a three-fold increase in nuclear size and nucleolar enlargement). It is an uncommon condition and therefore only a few small series have attempted to assess the associated risk of subsequent malignancy, particularly when diagnosed on core biopsy.
Design: Using our computerized database, we retrospectively identified, reviewed and confirmed the diagnosis of AAA in 32 cases (.02%) on core biopsy from 2000 to present. We excluded all cases with associated necrosis or conventional atypical duct hyperplasia (ADH). All clinical information including follow up information was gathered and radiologic-pathologic correlation was performed. Excision specimens were also reviewed for pathology and previous biopsy site changes.
Results: The patients ranged in age from 33 to 79 years (mean=56.5). The method of core biopsy was as follows: stereotactic for calcifications = 19, ultrasound (US) guided for a nodular mass = 7 and MRI for enhancement = 6 (4 with a recent or remote history of breast carcinoma). The indications for the calcifications on stereotactic biopsies were as follows: clustered = 16, new = 1, granular = 1, and linear = 1. Follow up information was as follows: excision = 23, patient refused excision = 3 (with >2 years stable radiologic follow up), and lost to follow up = 6. The diagnoses on excision were as follows: ductal carcinoma in situ (DCIS), apocrine type = 9, residual AAA = 3, no residual AAA = 11. Five of the 9 cases upgraded to DCIS were performed stereotactically and showed residual calcifications in both AAA and DCIS. The remaining 4 cases were obtained by MRI (1) and US (3); the latter 2 also had residual AAA on excision in addition to DCIS.
Conclusions: AAA represents a borderline lesion in the spectrum from apocrine metaplasia to apocrine DCIS. Given its rarity, our series was limited by number but nevertheless showed an upgrade rate to DCIS of 39% (9/23). Thus, AAA diagnosed on core biopsy should be excised due to associated sampling error and possible upgrade to DCIS.
Category: Breast

Monday, March 4, 2013 1:00 PM

Poster Session II # 40, Monday Afternoon


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