Fine-needle aspiration cytology and core biopsy of nonpalpable breast lesions.

Interest in fine-needle aspiration cytology (FNA) and core biopsy of nonpalpable breast lesions as an alternative to surgical biopsy has increased during the past year. The most accurate results have been reported with large-core needle biopsy using a dedicated prone stereotactic unit and stereotactic FNA biopsy obtained with an onsite cytopathologist determining sample adequacy. Ultrasound-guided needle biopsy using either FNA or core is another important technique. Questions remain concerning 1) the accuracy of FNA and core compared to surgical biopsy; 2) the efficacy of needle guidance by a mammographic add-on upright unit, dedicated prone table, or ultrasound; and 3) the lesions best suited for various biopsy techniques. Currently these nonsurgical biopsy methods are most appropriately used in conjunction with mammographic-histologic or cytologic correlation and a careful clinical management plan.