Heterogeneity of DNA distribution pattern in colorectal carcinoma. A microspectrophotometric study of fine needle aspirates.

For 50 consecutive patients with colorectal carcinoma, the nuclear DNA content in four separate fine needle aspiration samples taken from the resected tumors was analyzed using single-cell Feulgen cytometry. The DNA distribution patterns were divided into four classes according to their degree of euploidy/aneuploidy. Twenty tumors (40%) displayed a similar DNA pattern in all four samples while 30 tumors (60%) were heterogeneous, with a different DNA pattern within one or more of the four samples. None of the tumors were homogeneously diploid. These results illustrate the importance of multiple biopsy samples in the evaluation of the DNA pattern in colorectal tumors.