Stereotactic cytology in a regional breast-screening programme.

Stereotactic localization and fine-needle aspiration are new procedures for the management of non-palpable mammographic abnormalities. In this prospective study, stereotactically guided cytology with immediate reporting was performed before biopsy in a consecutive series of 166 patients with screen-detected non-palpable abnormalities. All specimens were obtained by multiple stereotactically guided passes with a 22-G Franzén needle and graded as: 1, acellular or inadequate; 2, benign; 3, atypical, probably benign; 4, probably malignant; or 5, malignant. After definitive surgery all tumours were staged according to the Union Internacional Contra la Cancrum classification. Of 71 patients with malignancy, 56 were correctly diagnosed by cytology before operation. Twelve patients with malignancy had grade 1 cytology and 50 of the 52 with grade 2 cytology had benign disease. This study confirms that stereotactic cytology is a valuable diagnostic test in a breast-screening programme.