BREAST STEREOTAXIC CORE BIOPSY WASHINGS - ABUNDANT CELL SAMPLES FROM CLINICALLY OCCULT LESIONS FOR FLOW CYTOMETRIC DNA ANALYSIS

RATIONALE AND OBJECTIVES. The object of this study was to determine by flow cytometry the cellular and DNA content of the washings of core b iopsy samples and needles obtained during stereotactic core biopsies o f clinically occult suspicious lesions. METHODS. Fourteen-gauge core m ultipass biopsy inner-needle saline washings obtained after dislodgmen t of the tissue core samples (n = 30) and 14-ga mammotomy core biopsy specimen washings (n = 30) were analyzed by flow cytometry. RESULTS. M ultipass core biopsy needle washings of 7 malignant and 23 benign lesi ons yielded a median of 10,584 cells per lesion (range 562-29,019 cell s). Mammotomy core biopsy specimen washings of 10 malignant and 20 ben ign lesions yielded a median of 12,164 cells per lesion (range 1,295-1 15,150). Forty-four (73%) washings in each technique had more than 500 0 cells, Flow cytometric DNA ploidy analysis was possible in 60 (100%) and the S phase percentage determination was possible in 59 (98%) of the washings, Aneuploidy was detected in 53% of malignant lesions and 2% of benign lesions. CONCLCUSIONS. Core biopsy specimen or needle was hings provide abundant fresh cellular material from clinically occult lesions for DNA analysis by from cytometry.