Ultrasound guided fineneedle aspiration of impalpable breast nodules

This study was designed in an attempt to improve the sensitivity of cytologic examination of fineneedle aspiration biopsies.

A prospective study was carried out on 79 patients with breast lesions less than 1 cm in diameter and clinically impalpable who were referred to the Radiodiagnostics Section of the Ca' Granda Hospital of Milan in 1990 and 1991 for mammographic and ultrasound verification. The examination was carried out using a high frequency (10 MHz) ultrasound probe to which an aspiration needle had been soldered. This made it possible to quickly and accurately reach the target nodule and thus gave a high sensitivity of the examination (93%). However, attachment of the needle to the probe prevented sampling from other points of the nodule and was responsible for the slight increase in number of inadequate samplesfi which in turn worsened the specificity of the test (86%). To check the gold standard of the examination, all the patients with positive or doubtful aspirations underwent surgical biopsy, whereas strict radiologic controls were performed in the negative cases.

Ultrasound-guided fineneedle aspiration may have advantages over needle aspiration performed with the stereotactic radiologic technique. The needle can be monitored even if the patient moves; even deep, peripheral nodules as well as those near a prosthesis can be reached; repeated samples can be taken, and costs are limited.