DNA CONTENT IN CERVICAL-CARCINOMA - A FLOW CYTOMETRIC ASSESSMENT OF DNA HETEROGENEITY

The degree of DNA heterogeneity varies between tumors arising in diffe rent body sites. Any substantial degree of variability within a given tumor can give rise to significant problems in the interpretation of D NA flow cytometric (FCM) studies. This study was undertaken to evaluat e the degree of DNA heterogeneity in cervical carcinomas. A total of 1 00 3-mm punch biopsies were evaluated from single large cases in 10 se ctions of cervical carcinoma. Of the 10 tumors, 6 were squamous carcin oma, 1 was an adenocarcinoma, 1 was a mixed small cell and squamous ca rcinoma, 1 was an adenosquamous cancer, and I was a small cell carcino ma with a small area of adenocarcinoma. Adequate histograms were avail able for 95 (95%) of the samples. Of the 10 cases studied, 9 (90%) rev ealed homogeneity in the DNA pattern. A solitary case demonstrated het erogeneity in one histogram (nine samples DNA diploid and one sample D NA aneuploid). This case was predominantly small cell undifferentiated carcinoma with focal adenocarcinoma. The area of adenocarcinoma was p robably the area that contributed to the heterogeneous FCM pattern. Fr om this study we conclude that for most cervical carcinomas of a speci fic histologic type there is DNA homogeneity. However, for carcinomas with a mixed morphology, DNA heterogeneity is possible and this must b e taken into account in any DNA ploidy studies that include mixed or c ombined tumors.