Objective: To investigate (1) the feasibility of preparing cell blocks by inverted filter sedimentation (IFS-CB) from endometrial samplings processed by the ThinPrep (TP) technique (Cytyc Corp., Boxborough, Massachusetts, U.S.A.), and (2) the possibility of increasing the diagnostic accuracy of TP endometrial cytology by examining the tissue architecture as an adjunctive method of detecting endometrial lesions.
Study design: Three hundred one endometrial samplings were obtained, using the Endogyn endometrial device (Biogyn S. n.c., Italy), from perimenopausal and postmenopausal women. The endometrial samplings were collected in a vial with liquid fixative for the TP processing. One TP slide was prepared from each case. If adequate material remained in the vial after the TP slide preparation, it was processed for IFS-CB preparation.
Results: IFS-CB preparation was processed in 263 cases (87%) with adequate material. Diagnoses on IFS-CB preparations obtained by endometrial sampling matched those of the hysterectomy specimens. The addition of IFS-CB histology to the cytologic diagnosis by TP increased the diagnostic accuracy of endometrial cytology to 96.3% and 100% for benign/atrophic endometrium and adenocarcinoma, respectively (p = 0.39 and 0.46). In hyperplasia without atypia and hyperplasia with atypia, the diagnostic accuracy increased significantly, to 96% and 95.3%, respectively (p = 0.037 and < 0.001).
Conclusion: This study illustrates the merit of linking TP cytology with direct endometrial sampling, including small tissue fragments and material adequate for IFS-CB preparation. TP cytology provides an accurate cytologic diagnosis and the possibility of IFS-CB preparation, which could be a valuable diagnostic adjunct to TP cytology.