Cytomorphology of Fibrocystic Change, High-Risk, and Premalignant Breast Lesions

Abstract

: Fine-needle aspiration biopsy has proven to be an accurate and well-tolerated procedure with a reported specificity of 99% and sensitivity of 70–99%. Similarly, nonpalpable breast lesions can be effectively sampled by needle biopsies under radiologic guidance. Breast aspirates have also been extensively utilized for assessment of nuclear grade, hormone receptor status, ploidy status, and proliferation rate, and have proven to be an attractive alternative to surgical biopsy. Using strict cytologic criteria, it may also be possible to recognize the cytomorphologic changes in breast lesions that are associated with increased risk for subsequent development of breast cancer. Presence of myoepithelial cells within the clusters of atypical epithelial cells recognized morphologically and/or detected by immunostaining for muscle specific actin is an important diagnostic feature of proliferative breast disease with atypia (atypical hyperplasia). This recognition has significant clinical implications and is important in the design of chemoprevention trials. The cytologic distinction between carcinoma in situ and invasive breast cancer remains difficult.