The role of ultrasound-guided needle aspiration of breast masses.

Ultrasonically guided aspiration cytology is an accurate and cost-effective method for managing sonographically indeterminate breast masses (masses that do not have all the ultrasonic criteria of simple cysts). Forty-five breast masses were aspirated. Of these, fifteen (33%) were atypical cysts, twenty-one (47%) were benign solid masses, three (7%) were malignant and six (13%) were solid lesions with nondiagnostic aspirate material. Since the tip of the needle is ultrasonically identified within the mass prior to aspiration, the accuracy of tissue sampling is potentially greater than with palpation alone. Lesions over five millimeters in diameter can be reliably sampled for cytology. This method can reduce the number of surgical biopsies performed by distinguishing atypical cysts from benign solid lesions and detecting malignant lesions when small. The simplicity of the technique encourages its use whenever an ultrasound study detects a noncystic mass.