Implementation of Precaptured Videos of Thyroid Fine-Needle Aspiration Cytology Specimens for External Quality Control Purposes

Research Article

Austin J Pathol Lab Med. 2021; 8(1): 1029.

Implementation of Precaptured Videos of Thyroid Fine-Needle Aspiration Cytology Specimens for External Quality Control Purposes

Archondakis S*

Department of Cytopathology, Alpha Prolipsis Cytopathology Laboratories, Greece

*Corresponding author: Stavros Archondakis, Department of Cytopathology, Alpha Prolipsis Cytopathology Laboratories, 1 Xenias St, Athens, 12137, Greece

Received: December 31, 2020; Accepted: January 12, 2021; Published: January 19, 2021


Objective: The objective of this study was examine the feasibility of developing a proficiency testing scheme for cytology labs wishing to be accredited according to ISO 15189:2012, by using videos captured by static telecytological applications.

Methods: The current study was carried out on 252 adequate specimens of 157 patients, retrospectively selected from the department’s registry. In all cases, surgical excision followed the initial cytological diagnosis. Three diagnostic categories of cytological reports were used. All cases were confirmed by histological diagnosis of surgical specimens. One representative video from each case was transferred via file transfer protocol to password-protected accounts for remote review by 3 independent cytopathologists. In addition to diagnosis, reviewers commented on overall digital video quality. Contributor’s and reviewer’s diagnoses were collected, recorded and statistically evaluated.

Results: Statistical evaluation of cytological diagnoses detected no significant difference in diagnostic accuracy between the diagnoses proffered on the basis of precaptured videos and conventional slides. The overall interobserver agreement was ranging from substantial to almost perfect.

Conclusions: Videos production by static telecytology applications can be used as an alternative method for cytological diagnosis validation. It is a prompt and valid method for quality assessment and proficiency testing and can be integrated into daily workflow. Pre-captured videos can improve significantly small cytology departments’ quality indices. Precaptured videos can also be used for teleconsultation and second opinion purposes and improve the performance of the already existing static telecytology stations.

Keywords: Telecytology; Liquid-based cytology; Thyroid; Accreditation; Quality control; Fine-needle aspiration; Videos


Accreditation is the process by which a certified organization or agency recognizes that a facility or service meets specific preestablished standards. ISO 15189:2012 constitutes an international accreditation standard, which can be used by medical laboratories wishing to improve their quality standards. Its requirements consist of a group of general guidelines that will help laboratories establish and enhance their quality systems [1-4]. According to ISO 15189:2012 requirements, one of the greatest challenges facing cytology laboratories is the design and implementation of a board certified external quality control program [1-4]. The purpose of the adopted program should be to ensure that microscopic (cytological) findings are correctly identified and interpreted by laboratory personnel [1-3]. Telecytology is the interpretation of cytology material at a distance using digital material (images or videos) [5-8]. Telecytology can be used for teaching, professional assessment, auditing, archiving, quantitative cytology and research, obtaining expert opinions on difficult cases, and routine diagnosis of the entire laboratory workload [5-7]. Telecytological diagnosis can be achieved either with the use of cytological pictures viewed in real time from the microscope (dynamic telecytological systems) or with the use of cytological pictures that are first captured in a digital format and then transmitted using a storeand- forward approach to distant observers (static telecytological systems) [6-9]. In its simplest form, a static system comprises of a digital microscopic workstation comprising of microscope attached to a camera and a computer with high processing capacity and modem or internet connections. Digital images are transferred via file transfer protocol to specific password protected accounts, via secure hypertext protocol using a 40-bit encrypted server on the world wide web via an adaptable telepathology video management system or via Multipurpose Internet Mail Extensions (MIME)-encapsulated e-mail attachments [7-10]. Diagnoses made using telecytology should be as reliable as those made using conventional microscopy [1,3]. The existing studies which focused on the possible impact of static telecytology in the everyday laboratory’s workflow have found a high concordance between telecytological and glass slide diagnoses [8-12]. However, little information exists about precaptured videos probable use for proficiency testing purposes [13]. Thus, the purpose of the article is to examine the feasibility of developing a proficiency-testing scheme for cytology labs wishing to be accredited according to ISO 15189:2012, by using precaptured videos.

Materials and Methods

The current study was carried out on 252 thyroid fine-needle aspiration specimens from 157 patients preoperatively aspirated under ultrasonographic guidance. For the purpose of this study, the 252 histologically confirmed cases were retrospectively selected from the department’s registry, as well as copies of the original cytological and histological reports. The material collected was prepared by the ThinPrep2000 automated slide processor (CytycCo. [now Hologic®, Bedford, MA]). From each case, one slide was prepared, stained by the Papanicolaou method, and examined by 3 independent board-certified cytopathologists. Conventional light microscopy was performed individually on an Olympus CX 31 microscope. Cytology reports were collected and statistically elaborated. The initial cytological diagnoses, made by conventional light microscopy, were made separately by each participant. In case of any major discrepancy, the final diagnosis was made after consultation and consensus of all participants. The initial cytological reports of each participant were kept for further statistical analysis (comparison with histology and measurement of intraobserver reproducibility between conventional cytology and telecytology made by precaptured videos). An other cytopathologist collected all 252-glass slides and captured 1 representative video from each case. Videos were captured with a Hamamatsu C4742-95 digital camera (Hamamatsu Photonics, Herrsching am Ammersee, Germany) mounted on an Olympus CX 31 microscope. The camera was connected via SCSI interface to a 1, 200-MHz Pentium CPU running Windows XP (Microsoft, Redmond, WA). Only one cytopathologist was assigned to capture 1 representative video from each case, in order to ensure homogenization of the criteria applied in field selection. The person appointed to capture representatives videos possessed adequate diagnostic experience and had not participated in the initial diagnostic round in order to avoid any bias concerning field selection. The videos captured were of 100 seconds duration each and provided valuable information that is routinely used in cytological diagnosis, such as background, cellularity, and nuclear and cytoplasmic details. More specifically, the criteria usually adopted for the selection of the captured areas were high cellularity, absence of obscuring factors, excellent preservation and visualization of nuclear and cytoplasmic details, background details (colloid), metaplastic changes, reactive cellular changes or cytological atypia (when present). The area covered by each video was about 20% of the slide area. All videos contained areas of both 100x and 400x magnification. The videos magnification was changing during video capture in order to focus to specific areas of interest. The intention of the study was to provide to all participating cytopathologists adequate digital material for making accurate diagnosis, without any methodological bias that could compromise the results of our study. All videos captured areas of interest at 100x and 400x magnifications with1, 124× 1,120 resolution at 16-bit color depth and 300 dpi. 6, 12 and 24 months after videos capture, all 252 collected representative videos were transferred via file transfer protocol to specific password-protected accounts and were reviewed remotely by the same 3 cytopathologists on workstations using Google Chrome Web browser. All videos were accompanied by an electronic record of all crucial medical data that could have impact on the cytological diagnosis of all samples included in our study, such as patient age, relevant ultra-sonographic findings, thyroid hormonal status and past medical history. Reviewers commented on overall video quality using a 10-step scale, from 1 (very poor) to 10 (excellent). Reviewers had adequate experience to work with digital material and to use internet applications for diagnostic purposes. The diagnostic approach of precaptured videos concerning criteria of diagnosis, terminology of lesions, requirements of adequacy, and recommendations for further management were similar to those applied in conventional cytology (the 2017 Bethesda System for Reporting Thyroid Cytopathology) [14]. A detailed discussion of diagnostic criteria was not conducted between the cytopathologists, but all available clinical information was provided to all participants. Primarily, the cytological reports were classified in three basic diagnostic categories. “Benign”, “malignant” and “suspicious” diagnoses were adopted. Diagnostic categories and their subclassification are presented in (Table 1). Cohen’s κ statistic was used for the calculation of intraobserver reproducibility. Mean intraobserver reproducibility was calculated as the weighted average of the individual kappa values. To determine the significance of the intraobserver kappa values, we used the Svanholm formula [15,16]. To assess interobserver agreement among cytopathologists for different diagnostic categories, kappa (j) statistics, first introduced in 1960, which provides a measure of agreement between two observers, was applied. Interpretation of kappa values is shown in (Table 2). Since our study involves more than two observers, a modification of kappa statistics allowing the comparison of more than two observers providing nominal (i.e. not ordered) answers, first proposed by Fleiss in 1971 was used [15,16].