Surgical follow-up results for apocrine adenosis and atypical apocrine adenosis diagnosed on breast core biopsy.

Apocrine adenosis (AA) and atypical apocrine adenosis (AAA) are uncommon findings in breast biopsies that may be misinterpreted as carcinoma. The clinical significance and risk implications of AAA diagnosed on core biopsy are not well established. This study aimed to determine the frequency of carcinoma on follow-up excision in patients with a diagnosis of AA or AAA on core biopsy. Forty-one breast core biopsies of AA (n=29) and AAA (n=12) were identified during a study period of 12 years. Of the 41 core biopsies with AA or AAA, 10 biopsies showed coexisting/concurrent atypical hyperplasia or carcinoma. In the absence of coexisting/concurrent atypical hyperplasia or carcinoma in core biopsy, none of the follow-up excision specimens after a diagnosis of AA or AAA showed ductal carcinoma in situ or invasive carcinoma. In conclusion, AA or AAA by itself is an uncommon core biopsy diagnosis that may not require surgical excision.