Comparison of needle aspiration and solid biopsy technics in the flow cytometric study of DNA distributions of surgically resected tumors.

Flow cytometric analysis (FCM) of DNA content of nuclei was performed on simultaneously obtained tissue samples and needle aspirates from 37 primary colorectal cancers and from 21 other tumors. There was a marked increase in the proportion of the nondiploid cell population in 18 of 58 aspirates when compared with the corresponding tissue samples, presumably because of selective aspiration of tumor cells. The difference was significant at level alpha much less than 0.01 by a paired t-test and was most pronounced in tumors wherein a nondiploid population constituted more than 20% of the sample. The difference did not correlate with the grade or stage of the tumor. These observations suggest that the sampling of surgically resected tissue specimens for DNA analysis by FCM is performed best by needle aspiration, which may increase the yield of nondiploid cells, does not interfere with histologic diagnosis, and may prove especially useful in the analysis of small surgical specimens.