Whole-Slide Imaging of Pap Cellblock Preparations Is a Potentially Valid Screening Method.

OBJECTIVE: To date, the impact of digital imaging on routine cytology remains far from perfect. Cellblock (CB) preparations from Pap samples have been shown to be diagnostically valuable. We evaluated the validity of utilizing whole-slide imaging (WSI) prepared from Pap CBs as a screening tool. STUDY DESIGN: A total of 1,110 CB slides prepared from residual Pap samples were analyzed - 563 normal, 282 atypical squamous cells of undetermined significance (ASCUS), 12 atypical squamous cells-cannot exclude high-grade squamous intraepithelial lesion, 188 low-grade squamous intraepithelial lesions (LSIL), 36 high-grade squamous intraepithelial lesions (HSIL), 25 atypical glandular cells of undetermined significance, 1 adenocarcinoma in situ, 2 invasive adenocarcinomas, and 1 squamous cell carcinoma. Virtual slides were obtained using the Aperio system. Test performance characteristics of liquid-based samples and WSI from CB samples were compared. RESULTS: Average sensitivity and specificity of the five WSI reviewers was 58.3 and 85.1% for ASCUS, respectively, 54.1 and 93.9% for LSIL, and 51.8 and 98.8% for HSIL. Overall WSI sensitivity and specificity for detecting lesions was 82.1 and 86.2%, respectively. Agreement (kappa values) between WSI reviewers was 0.56 for ASCUS, 0.69 for LSIL, 0.67 for HSIL, and 0.74 for negative samples. CONCLUSIONS: WSI of CB preparations is a feasible method to achieve high-quality specimen preparations. It is as sensitive as liquid-based methods and appears to be highly specific for the detection of LSIL and HSIL.

Whole Slide Imaging of Pap Cell Block Preparations versus Liquid-Based Thin-Layer Cervical Cytology: A Comparative Study Evaluating the Detection of Organisms and Nonneoplastic Findings.

OBJECTIVE: Cervical cancer is one of the most common malignancies worldwide, yet it is preventable by population screening. In a previous study, we confirmed the feasibility of utilizing whole slide imaging (WSI) of cell block (CB) preparations to overcome the limitations of digitizing cytologic samples. In this study, we evaluated the accuracy of WSI in identifying various organisms and nonneoplastic findings. STUDY DESIGN: A total of 335 WS images from Pap CB preparations were analyzed using the Aperio system. The test performance characteristics of ThinPrep (TP) and WSI samples were compared for adequacy, for the presence of bacterial vaginosis (BV), fungi, Trichomonas vaginalis (TV) and herpes simplex virus (HSV) and for nonneoplastic findings. RESULTS: The WSI samples contained optimal material from all preparations. BV was diagnosed in 33 WSI versus 36 TP samples. Budding yeasts and/or pseudohyphal forms were noted in 18 WSI versus 19 TP samples. TV organisms (10 of 11 samples) and 1 HSV case were accurately identified in the WSI and TP samples. Squamous metaplasia, keratosis and reactive/reparative and inflammatory changes were easily identified by WSI. CONCLUSIONS: The concept of WSI from Pap CB preparations is potentially feasible for adoption. Digital remote web-based technology eliminates the need for an individual on site, saving time and resources.