16 year experience with aspiration of noncomplex breast cysts: cytology results with focus on positive cases.

We performed a retrospective review of 5375 aspirations performed during the last 16 years of noncomplex cysts. Cytology results and outcomes following aspirations of simple and complicated cysts performed by the senior author at our institution were reviewed. Complex cysts with associated solid components which were core biopsied are excluded from this review. We present our data as the largest series to date performed by one breast radiologist at a single institution. Our data separate cysts with atypia or malignant cytology into those sampled concurrently with solid neoplasms and those which were isolated lesions. Various technical issues which have not been previously addressed in the literature are discussed. Noncomplex cysts are benign 99% of the time. Cysts with papillary cytology require no further workup. Margin-negative seromas do not require cytologic analysis of fluid. Sixteen malignancies were revealed (0.3%), eight of which were solitary cysts (0.1%). Atypical cytology predicted malignancy in 21%; therefore, atypical cytology requires further workup. Malignant cytology was associated with breast cancer in 90.9% of patients; therefore, all patients with malignant cytology require biopsy.