The significance of columnar cell lesions are frequently identified in core needle biopsies performed for calcification. The management of these lesions particularly in the atypia, is a subject of controversy. Several studies have raised the possibility that these lesions are preneoplastic and precede the development of invasive carcinoma. It has been suggested that an excisional biopsy. In contrast. other reports indicate that these lesions have a low risk of progression to carcinoma. Therefore, the goal of this study was to determine whether the authors could identify histopathologic features which could predict which lesions should be excised and which are unlikely to have higher-risk disease. Materials and methods: the authors identified 28 patients who underwent directional vaccum-assisted core needle biopsies for breast micro calcifications and subsequently had surgical resection. Twenty-eight paired core needle biopsy and surgical resections of columnar cell lesions were retriewed and evaluated by two pathologists base on previously defined criteria. Results: All 5 cases of columnar cell lesions without atypia showed no additional pathologic findings in the resection specimens. In the 4 cases of columnar cell lesions with atypia, the lesions were confined to or or = 3 lobular units/ducts, in 1 of these3 cases, ductal carcinoma in situ was found upon excision. Conclusion: The extent of columnar cell lesions/atypical ductal hyperplasia correlated with the presence of absence of higher risk lesions on subsequent excision. These results suggest that additional surgery may not be necessary for columnar cell lesions with atypia or atypical ductal hyperplasia that is limited to or