Incidental Finding of Abnormal Cervical Pathology in Hysterectomy Specimens after Normal Preoperative Papanicolaou Smears in Thammasat University Hospital

Background: To investigate abnormal cervical histopathology (ACH) from hysterectomy specimens withnormal preoperative Papanicolaou (Pap) smears. Materials and
Methods: Medical records from May 2009to April 2012 were retrospectively reviewed of subjects from whom hysterectomy specimens were taken inThammasat University Hospital. All had normal preoperative Pap smears. ACH was the primary outcome. Ap-value less than 0.05 was considered significant. A total of 483 subjects with an average age of 50.5 years wererecruited. Benign cases of enlarged uterus and pelvic mass were present in 94% (430/483). Endometrial andovarian cancer were found at 6.2 and 4.7%, respectively. In hysterectomy specimens there were 19 (4%) casesof ACH. Silent ACH with benign disease, endometrial and ovarian cancers were 1.2% (5/430), 33.3% (10/30)and 17.4% (4/23), respectively. The negative predictive value (NPV) and false negative rate of Pap smears were96 and 4%, respectively. ACH in malignant cases were 27.9% (12/43) and 20% (2/10) in adequate (APS) andinadequate (IPS) Pap collection groups, respectively. ACH in benign condition were 0.68% (2/292) and 2.2%(3/138) in APS and IPS, respectively. ACH was more often found in hysterectomy specimens with indication ofmalignancy than benign conditions with statistical significance. One third of preoperative stage I endometrialcancer cases had cervical involvement.
Conclusions: Silent ACH in normal preoperative Pap smear was 4%. Inadequate Pap smear collection is still the major problem in this study. Reducing inadequate Pap smearcollection could reduce the false negative rate.