Lobular carcinoma in situ or atypical lobular hyperplasia at core-needle biopsy: is excisional biopsy necessary?

PURPOSE: To retrospectively determine frequency of invasive cancer or ductal carcinoma in situ (DCIS) at excisional biopsy in women with atypical lobular hyperplasia (ALH) or lobular carcinoma in situ (LCIS) at percutaneous core-needle biopsy (CNB). MATERIALS AND METHODS: Review of results in 6,081 consecutive patients who underwent CNB at two institutions revealed that in 35 (0.58%), LCIS (n = 15) or ALH (n = 20) was the pathologic finding with highest risk. Patient age range was 41-84 years (mean, 59 years). Of 35 patients, 26 (74%) underwent excisional biopsy and nine (26%) underwent mammographic follow-up for longer than 2 years. Lesions with a pathologic upgrade were noted when invasive cancer or DCIS occurred at the CNB site. CNB results in patients with a diagnosis of atypical ductal hyperplasia (ADH) (75 of 6,081 [1.2%]) were reviewed; these patients underwent subsequent excisional biopsy. Statistical comparison of frequency of upgrading of lesions in patients with a diagnosis of LCIS or ALH at CNB and in those with a diagnosis of ADH at CNB was performed (Pearson chi(2) test). RESULTS: In six (17%) of 35 (95% CI: 4.7%, 29.6%) patients, lesions were upgraded to DCIS (n = 4) or invasive cancer (n = 2). In 15 patients with LCIS diagnosed at CNB, lesions in four (27%) were upgraded to either DCIS or invasive cancer. In 20 patients with ALH diagnosed at CNB, lesions were upgraded to DCIS in two (10%). Lesions in nine patients who underwent mammographic follow-up were stable. No mammographic or technical findings distinguished patients with upgraded lesions from those whose lesions were not upgraded. In 12 (16%) of 75 (95% CI: 7.7%, 24.3%) patients with ADH, lesions were upgraded. Difference between the upgrade rate in patients with LCIS or ALH and that in those with ADH was not significant (P =.88). CONCLUSION: Lesions in 17% of patients with LCIS or ALH at CNB were upgraded to invasive cancer or DCIS; this rate was similar to the upgrade rate in patients with ADH. Excisional biopsy is supported when LCIS, ALH, or ADH is diagnosed at CNB.