Percutaneous biopsies of the breast: state of the art.

Percutaneous biopsy of nonpalpable breast lesions can be performed using mammographic or ultrasound guidance. Stereotaxy is the only technique applicable to microcalcifications and very small masses. With few exceptions, discrete masses greater than 0.7-0.8 cm can be visualized on high-frequency sonograms. Because of the continuous real-time monitoring of the needle placement and of the sampling procedure, sonography has proved to be highly accurate and safe in experienced hands. In addition to depending on the accuracy of the radiologist in hitting the target and the accuracy of the cytopathologic diagnosis, the success of fine-needle aspiration biopsy depends on successful tissue extraction. The lack of significance of insufficient specimens and the importance of properly recording such results in the calculation of accuracy values for fine-needle aspiration biopsy are emphasized. On the other hand, confidence in a negative cytologic result (i.e., adequate specimen without malignant cells) of a perfectly guided procedure is a prerequisite for the nonsurgical management of nonpalpable breast masses and thus for reducing the number of surgical biopsies.