The use of fine-needle aspiration cytology and core biopsy in the assessment of highly suspicious mammographic microcalcifications: analysis of outcome for 182 lesions detected in the setting of a population-based breast cancer screening program.

BACKGROUND: Fine-needle aspiration biopsy (FNAB) is used as the first-line diagnostic test for lesions that require morphologic assessment in the authors' breast cancer screening program. A positive cytologic diagnosis is an indication to proceed to definitive surgery. Core biopsy is used if FNAB is not diagnostic. In the context of increased use of core biopsy at other centers, the authors reviewed their experience with the cytologic assessment of highly suspicious microcalcifications.
METHODS: Between January 1996 and June 2000, the dominant radiologic abnormality was classified prospectively as high-grade microcalcifications in 182 lesions. Data were recorded on patient demographics, radiologic features, and the findings of FNAB and core biopsy, if performed. The results of the screening assessment were then compared with the final histologic findings.
RESULTS: Overall, 15.6% of all radiologically high-grade lesions were microcalcifications. The mean patient age was 58.76 years. The lesions had a mean size of 38.49 mm (range, 5-200 mm), and 92.31% of high-grade microcalcifications proved to be malignant. Among the cases evaluated by FNAB, a positive cytologic diagnosis of malignancy was made in 70.93% of lesions, without any false-positive diagnoses and obviating the need for diagnostic core biopsy. FNAB had a sensitivity of 77.22% and a positive predictive value (PPV) of 100%. When core biopsy was performed due to the absence of a positive cytologic diagnosis, it averted the need for open biopsy in 76% of lesions.
CONCLUSIONS: Where there is access to skilled cytopathologists, FNAB can provide a highly accurate, rapid, and cost-effective means of triage of patients who would benefit most from the more expensive core biopsy. Copyright 2003 American Cancer Society.