Isolated Atypical Lobular Hyperplasia Diagnosed on Breast Biopsy: Low Upgrade Rate on Subsequent Excision With Long-Term Follow-up

Abstract

Context.— The upgrade rate to carcinoma on excision for atypical lobular hyperplasia diagnosed on breast biopsy is controversial. Objective.— To review cases with isolated atypical lobular hyperplasia on biopsy to establish the rate of upgrade on excision and correlate with long-term follow-up. Design.— A database search was performed for 191 months to identify breast core biopsies with isolated atypical lobular hyperplasia. Cases with other atypical lesions in the biopsy or discordant radiologic-pathologic findings were excluded. Invasive carcinoma and ductal carcinoma in situ were considered upgraded pathology on excision. Patients without and with a history of, or concurrent diagnosis of, breast carcinoma were compared. Results.— Eighty-seven cases of isolated atypical lobular hyperplasia on biopsy underwent subsequent excision, which resulted in 3 upgraded cases (3.4%). All 3 cases with immediate upgrades revealed ductal carcinoma in situ. Upgrade was higher in patients with a concurrent diagnosis of breast carcinoma (2 of 26 and 1 of 61; 7.7% versus 1.6%, respectively). Follow-up information was available for 63 patients (57.8 ± 43.9 months; range, 6–183 months). Overall, 13% of patients without a history of breast carcinoma had a future breast cancer event, with the majority (83%) presenting in the contralateral breast. Conclusions.— With careful radiologic-pathologic correlation, the upgrade rate for isolated atypical lobular hyperplasia on biopsy is low, and a more conservative approach may be appropriate.