MAMMOGRAPHIC-HISTOPATHOLOGIC CORRELATION OF LARGE-CORE NEEDLE BIOPSIES OF THE BREAST

Large-core (14g) needle biopsy (CNB) of the breast is a new diagnostic modality increasingly being used to evaluate patients with mammograph ic abnormalities. Two hundred twenty-four CNBs were performed on 198 p atients. Surgical follow-up was available in 64 cases (28.6%), Overall concordance rate was 93.8% (60 of 64 cases). Of the four discordant c ases, two were diagnosed as atypical ductal hyperplasia (ADH) on CNB; on excision, these cases showed cribriform ductal carcinoma in situ (D CIS); two remaining cases, diagnosed on CNB as ADH versus DCIS, showed invasive carcinoma (DCIS with invasive component and infiltrating cri briform carcinoma, respectively) on excisional biopsy. Malignancy, pri mary (52) or metastatic (5), was identified in 57 cases (25.4%); 47 of these patients underwent surgical excision, and the diagnosis was con firmed in all of these cases. Of 51 cases with radiographic evidence o f microcalcifications, 48 (94%) had microcalcifications in the CNB: 30 (62.5%) were benign, 11 (22.9%) were malignant, and 7 (14.6%) were di agnosed as ADH. In the remaining three cases (1.3%), only benign breas t tissue without micro-calcifications was seen, and the lesion was con sidered to have been missed, Biopsy specimens were obtained from 173 l esions because of the presence of a mass: 125 (72.3%) were benign, 45 (26%) were malignant, and 3 (1.7%) were diagnosed as ADH. Follow-up wa s available in 118 patients with benign lesions: all were mammographic ally stable or decreased at 6 or 12 months; no follow-up was available for the remaining patients. CNB of the breast is a highly sensitive ( 96.9%) and specific (100%) technique for management of patients with m ammographic abnormalities. The histologic findings should be correlate d with the mammographic appearance, and an attempt should be made to a chieve a specific diagnosis in all lesions, particularly masses. The d iagnosis of ADH should always prompt excisional biopsy because of a hi gh frequency of false-negative results caused by sampling errors or un derestimation.