Fine needle aspiration cytology of the breast - Experience at an outpatient breast clinic

OBJECTIVE: To evaluate the accuracy of fine needle aspiration cytology (FNA C) of the breast at our institution and to perform quality assurance. STUDY DESIGN: Two hundred forty-six cases with pathologic confirmation were selected and reviewed. A pathologist performed most of the aspirations at nit out-patient breast clinic. We correlated cytologic and histologic findi ngs and evaluated the influence of the size, location, grade, and pathologi c subtypes and fibrosis in breast lesions on diagnostic results. RESULTS: The likelihood ratios for malignant, suspicious, atypical, benign and unsatisfactory cytologic diagnoses were 98.71, 5.48, 1.09, 0.07 and 0.5 5, respectively. The absolute anti complete sensitivities for malignant les ions were 64.5% and 90.3%, respectively. The specificity was 71.9%. False n egative and positive rates weve 4.3% at-id 0.7%, respectively. The predicti ve value for a malignant cytologic diagnosis was 98.4%. The rate of unsatis factory samples was 9.3%. The rate of concordance between cytologic and his tologic diagnosis was lower for large and diffusely growing lesions (benign and malignant),for malignancies with abundant fibrosis and of unusual type s and for carcinomass of low grade. All axillary and recurrent chest wall l esions were diagnosed cytologically. Cell block sections were useful in a s mall number of cases. CONCLUSION: Understanding the performance and limitations of FNAC can enhan ce its value as a diagnostic technique in the management of breast disease.