DNA image cytometric analysis of differentiated thyroid adenocarcinoma specimens

A total of 117 differentiated thyroid adenocarcinomas that had been removed by total thyroidectomy were studied. Seventy (60%) were papillary, 36 (30%) were follicular, and 11 (10%) were Hürthle cell adenocarcinomas. The mean length of follow-up was 57.7 months. Adverse prognostic factors according to multivariate analysis were adjacent tissue infiltration (p = 0.0004), histologic type (p = 0.0049), and patient age (p = 0.033). The nuclear DNA content of tumor cells and of morphologically normal adjacent tissue was assessed by image cytometry, and correlations between nuclear DNA content and prognostic factors were examined. Fifty-four (75%) adenocarcinomas were classified as aneuploid, 9 (13%) as diploid, and 9 (12%) as borderline. Thirty-four (60%) specimens of morphologically normal adjacent tissue were classified as aneuploid, 18 (32%) as diploid, and 5 (8%) as borderline. The correlation between tumor ploidy and selected prognostic factors was statistically significant for patient age (p = 0.004) and histologic type (p = 0.033). Despite the fact that ploidy could not be identified as a prognostic factor, we suggest that, because of its correlation with age and histologic type, it might prove prognostic if the number of patients were increased. We also emphasize the importance of evaluating morphologically normal adjacent tissue because of the high rates of aneuploidy in these areas.