Follow-up surgical excision is indicated when breast core needle biopsies show atypical lobular hyperplasia or lobular carcinoma in situ: a correlative study of 33 patients with review of the literature.

Atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS) diagnosed in core needle biopsy (CNB) are generally regarded as risk indicators for developing invasive ductal or lobular carcinoma in either breast. Currently, there are no well-established guidelines for management of these patients. The most common management options are careful observation and endocrine chemoprophylaxis for high-risk patients. Previous studies had contradicting recommendations regarding follow-up surgical excision (FSE) of CNB yielding ALH or LCIS. These studies, unfortunately, have been limited by their retrospective nature, small number of patients examined, and association with other high-risk lesions. Only CNB diagnosed as pure LCIS or ALH (not associated with other high-risk lesions such as ADH, radial scar, or papilloma) were included in the study. We reviewed 33 CNB (20 ALH and 13 LCIS) with subsequent FSE from 33 patients (age range, 30-83 years; mean, 58 years). Eighteen of these patients were prospectively analyzed, where FSE was performed in an unselected fashion. All CNBs were obtained by mammotome (11-gauge, 30 cases; and 14-gauge, 3 cases). Mammography identified calcifications in 29 cases (88%) and a mass in 4 cases (12%). FSE revealed infiltrating ductal and/or lobular carcinoma in 4 of 13 LCIS (31%). FSE of 20 ALH revealed cancer in 5 cases (25%), including 4 ductal carcinoma in situ (DCIS) and 1 invasive lobular carcinoma. Seven of these nine cancers were associated with calcifications, and two presented as masses. Sampling error and underestimation of cancer (DCIS or invasive carcinoma) was associated with CNB diagnosis of LCIS or ALH in 27% of all cases. Underestimation of cancer was seen in 28% of prospectively examined patients, including 20% of ALH and 38% of LCIS. CNB associated with mass lesions or that showed histologic features of pleomorphic LCIS or extensive classic LCIS had a higher rate of cancer underestimation. Despite removal of all abnormal mammographic calcifications by CNB in 6 patients, one cancer was detected on FSE. To the best of our knowledge, this is the largest study reported to date, and the only one to include prospectively examined patients with no pre-selection bias. Our data strongly suggests that subsequent FSE is warranted in all patients with CNB diagnoses of LCIS or ALH, to exclude the presence of cancer.