Flow cytometric DNA analysis of excised breast lesions: use of fresh tissue needle aspirates obtained under guidance with mammography of the specimen.

Eighty consecutive biopsy specimens were studied to determine whether DNA analysis could be performed on fine-needle aspirates of excised clinically occult breast lesions obtained under guidance with mammography of the specimen before fixation to offer the advantages of fresh-tissue analysis. With use of single aspirates, cytologic analysis was possible in 50 cases (62%); DNA analysis was possible in 75 cases (94%). These methods combined offered no statistically significant increase in sensitivity for detection of malignancy compared with cytologic analysis alone. Forty-one percent of the analyzable invasive carcinomas showed aneuploidy. Aneuploidy and high S phase fractions of the invasive carcinomas showed no substantial correlation with patient age, nodal status, and size or appearance of the mammographic lesion. Aneuploidy was also seen in zero of four analyzable lesions showing ductal carcinoma in situ, two of 13 showing atypical hyperplasia (15%), and one of the 28 remaining benign lesions (4%). The authors conclude that this mammographic intervention is an effective means of obtaining fresh tissue samples of clinically occult lesions for DNA analysis.