Breast Lesions of Uncertain Malignant Potential: A Challenge for Surgeons

Objective and background: The need for surgical resection of breast lesions of uncertain malignant potential diagnosed by core-needle biopsy (CNB) is not well established. Our study sought to determine the incidence of these lesions at CNB and to find the rate of pathologic upgrade at surgery. and during clinical follow-up. Method: A retrospective review of CNBs performed at our hospital covering the period from November 1999 to December 2008 was undertaken. In those patients diagnosed with lobular neoplasia (atypical lobular neoplasia (ALH) and lobular carcinoma in situ (LCIS)), atypical ductal hyperplasia (ADH) and radial scar (RS) the rates of pathologic upgrade at subsequent surgery were determined. Results: 9325 breast CNBs were performed during the period under review. There were 36 diagnoses of ALH (0.4%), 20 of LCIS (0.2%), 110 of ADH (1.2%) and 60 of RS (0.6%). Regarding lobular neoplasia, ALH surgical resection was performed with subsequent pathologic upgrade in only 1/31 patients (3.2%). 85% of LCIS diagnoses were followed by surgical resection with pathologic upgrade in 5/17 cases (29%). For patients with ADH, 51% (56/110) had surgical resection with an upgrade rate of 20% (11/56). 9/54 patients (17%) who did not undergo surgical resection subsequently developed a cancer at the biopsy site. Regarding RS, in 58% (35/60) of cases surgical resection was undertaken with a pathologic upgrade rate of 8% (3/35). In all three cases with an upgrade the biopsy had been performed on a hypoechogenic lesion. Conclusion: We conclude that the significant rate of pathologic upgrade in LCIS and ADH mandates a surgical excision when these lesions are found at CNB. The low rate of pathologic upgrade in RS in the absence of a hypoechogenic lesion and ALH may allow these cases to be observed.