Factors affecting the under-diagnosis of atypical ductal hyperplasia diagnosed by core needle biopsies - A 10-year retrospective study and review of the literature

Introduction: Due to the possibility of underestimation, surgical excision is usually offered to patients with atypical ductal hyperplasia (ADH) diagnosed with core needle biopsy (CNB). Here we review the 10-year data of patients with ADH diagnosed by CNB, aiming to identify the factors associated with under-diagnosis. Methods: Retrospective review of database from 1st Jan 2005 to 31st Dec 2014 was performed; patients with ADH diagnosed by CNB were identified. Diagnosis upgrade rate and its risk factors were evaluated. Results: 104 patients were found to have ADH on CNB, 101 patients received excisional biopsy while 3 patients refused operation. 34 patients had ductal carcinoma in situ (DCIS) after excision, 6 had invasive ductal carcinoma, 1 had lobular carcinoma in situ and 1 had angiosarcoma. CNB under-diagnosed up to 41.6% of malignant lesions. Breast mass on presentation and suspicious mammograms (BIRADS >= 4) are associated with diagnosis upgrade (P = 0.0005, 0.0001). Literature review of 39 studies between 1997 and 2017 revealed 3125 excision procedures performed for ADH diagnosed by CNB, the pooled median diagnosis upgrade rate was 25% (Range 4-54%). Conclusion: We recommend excision in all patients with ADH diagnosed by CNB, especially in patients with suspicious mammographic features.