official website and that any information you provide is encrypted emailE=('rouse' + '@' + 'stan' + 'ford.edu') The purpose of this study is to examine the breast cancer risk overall among women with simple fibroadenoma or complex fibroadenoma and to examine the association of complex fibroadenoma with breast cancer through stratification of other breast cancer risks. P30 CA015083/CA/NCI NIH HHS/United States, P50 CA116201/CA/NCI NIH HHS/United States, R01 CA132879/CA/NCI NIH HHS/United States. 8600 Rockville Pike Background: To determine the cytomorphological features of complex type fibroadenoma (CFA), we reviewed fine needle aspiration (FNA) cytology with correlation to its histopathology findings, and compared them with non-complex type fibroadenoma (NCFA). Closely packed uniform tubules, lined by a single layer of epithelial cells and an attenuated myoepithelial cell layer. Approximately 16% of fibroadenomas are complex. The study included women aged 18-85 years from the Mayo Clinic Benign Breast Disease Cohort who underwent excisional breast biopsy from 1967 through 1991. Results: