DNA ploidy heterogeneity in endometrial carcinoma: comparison between curettage and hysterectomy specimens

DNA ploidy has been reported to be a prognostic marker for patients with endometrial carcinoma. In this study, DNA ploidy and histologic heterogeneity were evaluated by comparing curettage and hysterectomy specimens in 99 consecutive patients diagnosed with endometrial carcinoma. High-resolution DNA ploidy image analysis and review of histologic specimens were performed. The histologic subtypes were identical in 77 (78%) and differed in 22 (22%) cases. The DNA ploidy results were concordant in the curettage and hysterectomy specimens in 72 (72.7%) and discordant in 27 (27.3%) cases. Histologic heterogeneity was significantly associated with DNA ploidy heterogeneity (P=0.03). On the basis of histologic heterogeneity, DNA ploidy-discordant cases were divided into 2 groups. One group (16.2% of cases) consisted of specimens with similar histology in curettage and hysterectomy, all belonging to the endometrioid subtype. This group showed DNA ploidy discordance because of a DNA diploid peak in 1 specimen and an aneuploid peak (DI=1.05-1.2) in the other. The other group (11.1% of cases) consisted of cases with different histologic subtype or grade and showed a more pronounced DNA ploidy difference (diploid vs. aneuploid with DI>1.2). Our results suggest that the DNA ploidy results of the hysterectomy and curettage specimens are not identical. The difference observed, which we believe reflects the intratumoral heterogeneity, should be taken into account when applying DNA ploidy to endometrial carcinoma specimens.