Clinical parameters associated with unsatisfactory specimens of conventional cervical smears.

Although The Bethesda System 2001 attempted to standardize the criteria for specimen adequacy, much confusion still exists, which includes the significance of unsatisfactory smears, the causes and clinical conditions related to unsatisfactory smears, and the appropriate management of unsatisfactory smears. The aim of this study is to find out the clinical factors associated with unsatisfactory cervical smears. We reviewed the medical charts of patients who received conventional Pap smears between March 2006 and August 2006 in a tertiary care center. After excluding 378 cases with incomplete demographic data, the clinical data of 7,059 cases were processed for analysis. Clinical parameters retrieved included: history of pelvic malignancy, pelvic irradiation, conization, hysterectomy, pregnancy status, within 3-months postpartum. Vaginal bleeding, abnormal vaginal discharge, intrauterine device, and cervical polyps found during pelvic examinations were also documented. The 1,397 cases with history of pelvic irradiation, pelvic malignancy, and hysterectomy were excluded. Finally, 5,662 cases were enrolled for data analysis. The relationship between clinical parameters and unsatisfactory smears were analyzed by Pearson's chi-square test with Yates' continuity correction and multivariate binary logistic regression test. The incidence of unsatisfactory smears was 4.5% (252/5,662). Clinical parameters correlated with unsatisfactory smears were postpartum status (OR = 1.92, 95% CI = 1.23-3.01, P = 0.004), vaginal bleeding (OR = 2.02, 95% CI = 1.30-3.16, P = 0.002), and endocervical polyps (OR = 2.62, 95% CI = 1.39-4.947, P = 0.003). In conclusion, if any of these parameters are noted prior to obtaining a Pap smear, optimal collecting devices, better sampling techniques, and liquid-based cytology should be considered to decrease the incidence of unsatisfactory smears.

Should adequacy criteria in cervicovaginal cytology be modified after radiotherapy, chemotherapy, or hysterectomy?

BACKGROUND: The general criterion of an unsatisfactory Papanicolaou (Pap) test in the 2001 version of the Bethesda system is not applicable to patients after treatment with radiotherapy, chemotherapy, or hysterectomy. The current study was performed to determine whether specimen adequacy criteria for Pap tests should be modified for these conditions. METHODS: Consecutive patients who underwent conventional Pap tests between March and August 2006 were reviewed. The original reports were done according to the 2001 Bethesda system, with cellularity criteria modified in patients with a history of radiotherapy, chemotherapy, or hysterectomy. The slides of these patients were reviewed again. The degrees of cellularity, obscuring red blood cells, and inflammation were recorded. RESULTS: The final analyses included 7033 patients for which there were complete data. The original interpretation was unsatisfactory in 4.4% of all samples. When the 1337 slides obtained from patients with a history of radiotherapy, chemotherapy, and/or hysterectomy were reviewed using the general satisfactory threshold of >8000 squamous cells/slide and <75% of the epithelium obscured, the incidence of unsatisfactory Pap tests increased from 4.3% to 13.2% (176 of 1337 slides). The odds ratios for unsatisfactory Pap tests for a history of radiotherapy, chemotherapy, and age >50 years were 2.70, 2.51, and 1.39, respectively. The majority of unsatisfactory Pap tests were because of low cellularity. The lower limits of adequate cellularity after radiotherapy or chemotherapy can be set at 2000 cells/slide, which can lower the unsatisfactory rate while at the same time resulting in no increase in the false-negative rate. Hysterectomy alone was not found to be associated with unsatisfactory Pap tests. CONCLUSIONS: In patients who received pelvic radiotherapy or chemotherapy, the incidence of low-cellularity Pap tests was unacceptably high. A lower cellularity (estimated 2000 cell/slide) could be used as a satisfactory threshold.

Liquid-based cytology in diagnosing nasopharyngeal carcinoma.

BACKGROUND: Liquid-based cytology (LBC) has achieved great success in cytological diagnosis of various cancers when compared with conventional smear methods. However, its application in diagnosing nasopharyngeal carcinoma (NPC) has never been studied. METHODS: Eighty-four consecutive patients who underwent nasopharyngeal biopsy for suspicious NPC or a nasopharyngeal mass under nasopharyngoscopy were enrolled in this prospective study. Brush samples were taken from the same site before punch biopsy and processed with the Thin Prep test. RESULTS: The adequacy, accuracy, sensitivity, specificity, false-negative rate, and false-positive rate of LBC in diagnosing NPC were 92.9% (78 of 84), 93.6% (73 of 78), 84.2% (16 of 19), 96.6% (57 of 59), 15.8% (three of 19), and 3.4% (two of 25), respectively. There were four inadequate specimens from patients with NPC and two inadequate ones from those without NPC. CONCLUSIONS: Our study showed that the adequacy, accuracy, sensitivity, specificity, and diagnostic rate of LBC were equivalent to those using conventional smear methods. Although the diagnostic rate of NPC was lower using brush cytology than by punch biopsy, further improvements in the sampling technique could make brushing cytology a potential tool for NPC screening.