Performance Characteristics of Endometrial Cytology in a Hysterectomy-Controlled Environment

This section concerns estimating the degree of confidence that can be placed in endometrial cytology diagnoses. It asks, “How does an endometrial cytology diagnosis compare with the actual state of the endometrium?” and, “Does the diagnosis that we render on cytology material alone give the clinician sufficient data upon which to counsel and/or treat a woman, and does it allow the clinician to confidently decide whether ancillary procedures should be performed or not?” Studies designed to answer these questions have generally compared the outcomes of using various sampling devices to some gold standard such as dilatation and curettage or hysterectomy.

In our data set, about 90% of the office-based cytology collections have comprised diagnostic endometrial studies, less than 10% have been cellular studies limited to the endocervix and low uterine segment, and only 0.2% have been hypocellular and nondiagnostic. The difference between the Tao brush and standard tissue biopsy devices is that a failure to collect cytology or histology material (in the form of a cell block) is neither a function of advanced patient age nor of endometrial thickness. The thin endometria of elderly women can still yield adequate and informative cytology material. This characteristic is important when assessing benign endometrial states or thin endometrial lesions such as endometrial intraepithelial cancer or endometrial gland dysplasia (EIC/EmGD).