The importance of cytologic intrarater and interrater reproducibility: the case of ductal lavage.

The reproducibility of a test result is a critical component of its clinical utility. Little information is available concerning the intrarater reproducibility of cytologic assessments. This study evaluated the reproducibility of cytologic interpretation of epithelial cells obtained from ductal lavage (DL), a minimally invasive method used to obtain sample cells from breast tissue. Two cytospin slides were made for each duct sampled. Slides with <10 cells were considered inadequate to make a diagnosis; the remaining slides were classified into mildly atypical, markedly atypical, and malignant cells. Each pair of slides were classified by the more serious diagnosis. DL samples from 100 ducts were independently blind-reviewed by two experienced cytopathologists. All abnormal slides and a random sample of normal slides and slides identified as inadequate for diagnosis (n = 43) were re-reviewed. The kappa for intrarater agreement was 0.59 +/- 0.10 for cytopathologist 1 and 0.33 +/- 0.08 for cytopathologist 2. The kappa for interrater agreement of slides from 100 ducts was 0.46 +/- 0.07. The interrater agreement of the slides that were re-reviewed was kappa = 0.27 +/- 0.09. Fair to moderate intrarater and interrater agreement of DL cytology was observed. Low intrarater and interrater cytologic consistency may compromise the interpretation of clinical studies of DL.

Image quality issues in a static image-based telepathology consultation practice.

Field selection and image quality have often been identified as impediments in the successful employment of static-image telepathology. One thousand seven hundred fifty-three electronic consultations using static images were performed at the Department of Telemedicine, Armed Forces Institute of Pathology (AFIP) between November 1994 and September 2001, with 98.3% receiving a telepathology diagnosis. In 47.9% of cases, imagery was considered good by AFIP consultants, 38.5% were considered adequate, and 14.6% of cases were considered to have poor-quality imagery. Deficiencies in image quality were recorded for each case. Cases with imagery rated as good averaged significantly fewer deficiencies per case (0.45, range: 0 to 3) than cases with imagery rated adequate (0.95, range: 0 to 6) or poor (2.4, range: 0 to 7). Deficiencies in focus were most commonly identified in this series of cases (28.1%), followed by improper white balancing of the capture device (14.1%) and inadequate resolution (10%). Cases in which images were of inadequate resolution showed an increased likelihood for discordance between the telepathology diagnosis and the diagnosis rendered on follow-up material ("truth diagnosis"). Inadequate field selection, although only cited in 6.7% of cases overall, was seen with a significantly higher frequency in cases in which there was discordance between the telepathology and truth diagnosis. A review of common image deficiencies in static-image telepathology and possible causes is presented.

Comparative analysis of a liquid-based Pap test and concurrent HPV DNA assay of residual samples. A study of 608 cases.

OBJECTIVE: To retrospectively study the HPV DNA assay of residual samples from the ThinPrep Pap Test (Cytyc Corporation, Boxborough, Massachusetts, U.S.A.) PreserveCyt (Cytyc) vial as a quality improvement (QI) indicator for management of patients with abnormal cervical cytology. STUDY DESIGN: Six hundred eight residual sample vials of liquid-based Pap-Test specimens were selected for the study based on Pap-test results from October 1998 to March 2001. The specimen vials were forwarded to the reference laboratory (American Medical Laboratories, Chantilly, Virginia, U.S.A.) for HPV DNA assay using the Hybrid Capture System method (Digene Corporation, Gaithersburg, Maryland, U.S.A.). At the time of HPV DNA assay, the residual samples were between 8 days to 10 months old, and each vial contained 4 mL. Of the 608 study cases, 76 were WNL, 115 contained BCC, 172 contained ASCUS, 179 were LSIL and 66 were HSIL. In this study, the 191 WNL and BCC cases were designated as the disease-free control group. The HPV DNA typing results were reported as low-risk, high/intermediate-risk or HPV DNA "not detected" HPV types. The HPV DNA testing results were compared to the Pap-Test diagnoses and statistical analysis performed. RESULTS: The following information reflects the percentage of HPV DNA-positive cases based on the Pap-Test diagnoses: 16.2% in WNL and BCC, 51.1% in ASCUS, 94.4% in LSIL and 98.4% in HSIL. Sensitivity (95.5%), specificity (83.7%), false negative value (4.4%), false positive value (16.2%) and predictive value of a positive (88.3%) and negative (93.5%) Pap-Test were calculated on the basis of HPV DNA testing results for 436 cases that were diagnosed as either SIL or negative (WNL and BCC). ASCUS (172) Pap-Test cases were considered borderline--disease positive and excluded from statistical analysis. CONCLUSION: The HPV DNA assay of residual samples from ThinPrep Pap-Test liquid-based specimens is an objective adjunct to the gynecologic cytology QI protocol and is the gold standard reference test for triaging women with equivocal cytologic diagnoses. The great value of HPV DNA testing is its high sensitivity (95.5%), specificity (83.7%) and negative predictive value (93.5%). HPV DNA testing results can be used as a tool to better determine the need for referrals for colposcopic biopsy, especially for patients with an ASCUS diagnosis. The residual Pap-Test specimens are stable and reproducible for HPV DNA typing. A working flow chart for our gynecologic cytology QI program was produced from the Pap-Test and HPV DNA assay results. This offer presents the added benefit of minimizing the problem of sample variation. The prevalence of HPV infection was 16.2% in this study.