Management of nonpalpable ultrasound-indeterminate breast lesions

Background. A series of such lesions was studied to determine the validity of applying criteria routinely used to manage palpable breast cysts to the management of mammographically detected, nonpalpable breast lesions characterized as indeterminate on ultrasound (US). Methods. The clinicopathologic data from a series of 134 patients who underwent US-guided fine needle aspiration biopsy for nonpalpable, mammographically detected breast lesions, categorized as indeterminate on US, were reviewed. Results. Of 139 indeterminate lesions, 78 were consistent with complex cysts, whereas in 61, the cystic-versus-solid nature was indistinguishable. All 71 complex cyst lesions that contained nonbloody fluid and resolved completely were benign. Two of 7 complex cyst lesions that had incomplete resolution, bloody aspirate, or both were malignant. Of 61 cystic-versus-solid lesions, 29 and 32 were primarily solid and cystic, respectively. Three of the 29 solid lesions were malignant. Of the 32 cystic lesions, all 26 that contained nonbloody fluid and resolved completely were benign, whereas 1 of 6 lesions that had incomplete resolution, bloody aspirate, or both was malignant. Conclusion. Criteria such as complete resolution and nonbloody aspirate are an effective adjunct to the management- of nonpalpable, mammographically detected breast lesions categorized as indeterminate by US.