Liquid-based endometrial cytology: cyto-histological correlation in a population of 917 women

Liquid-based cytology, because of its capacity to reduce the obscuring factors and to provide thin-layer specimens, represents an opportunity to reevaluate endometrial cytology. In order to assess the utility of the liquid-based method in endometrial diagnosis, we evaluated its accuracy in comparison with histology.

Nine hundred and seventeen women scheduled for hysteroscopy were enrolled in the study. After providing informed consent, all the women proceeded sequentially to hysteroscopy, endometrial cytology and then biopsy endometrial sampling.

Cyto-histological correlations were possible in 519 cases (57%): in 361 (39%) cases the biopsy was inadequate, in 15 (2%) the cytology was inadequate, and in 22 (2%) both were inadequate. At biopsy 25 (3%) women had adenocarcinoma, 5 (1%) had adenomatous atypical hyperplasia and 21 (2%) had simple non atypical hyperplasia. At cytology two adenocarcinomas and one adenomatous atypical hyperplasia were underrated as atypical hyperplasias and as non-atypical hyperplasia; two simple non-atypical hyperplasias were reported as negative; and eight cases were false positive (non-atypical hyperplasia at cytology, negative at biopsy). In our population, the cytology provided sufficient material more often than biopsy (P < 0.04). Sensitivity was estimated at 96%, specificity at 98%, positive predictive value at 86% and negative predictive value at 99%.

We concluded that endometrial cytology may be an efficient diagnostic method. It could be applied to selected patients solely or in association with ultrasonography. The combination of these two noninvasive procedures may improve their diagnostic accuracy and reduce unnecessary hysteroscopies, thereby producing benefits for women and society.