Is core needle biopsy superior to fine-needle aspiration biopsy in the diagnosis of papillary breast lesions?

Since the 1980s core needle biopsy (CNB) has gained remarkable popularity and in many institutions it has replaced fine-needle aspiration biopsy (FNAB). However, similar to FNAB, limitation remains in the ability of this procedure to reliably diagnose a small, but prognostically significant, number of breast lesions. These include entities such as atypical ductal hyperplasia, fibro-epithelial tumors, radial scar, papillary lesions, and lobular neoplasia. To assess the diagnostic accuracy of CNB vs. FNAB in the same breast lesions, we reviewed our cases of papillary lesions of the breast. In a retrospective study, we identified 36 cases of FNAB and 11 cases of CNB diagnosed as papillary lesions and compared the results with their corresponding surgical specimen. Interpretation ranged from papillary vs. atypical papillary lesions favoring benign vs. malignant tumors, respectively. Occasionally, definitive diagnosis of papillary carcinoma was entertained. Immunohistochemical staining with smooth muscle actin was used to evaluate the presence or absence of a myoepithelial cell layer. FNAB had benign findings in 21 lesions, atypical in 10, and malignant in five. Of the five lesions yielding malignant features, four had invasive carcinoma and one had micropapillary ductal carcinoma in situ (DCIS). Surgery revealed invasive carcinoma in three of the cases interpreted as atypical papillary lesions and invasive cancer and micropapillary DCIS in three of the cases diagnosed as benign lesions. Similar results were obtained with CNB. DCIS was found in one out of six of the cases diagnosed as papilloma. Out of the four cases that were interpreted as atypical papillary lesion, surgery revealed invasive carcinoma in one case and one case had micropapillary DCIS. Diagnosis of malignancy was confirmed by histology in one case interpreted as papillary carcinoma by CNB. This study suggested that both FNAB and CNB share similar diagnostic challenges and a follow-up surgical excision is indicated when diagnosis of a papillary lesion is entertained by both procedures. Copyright 2003 Wiley-Liss, Inc.