Should Liquid Based Cytology (LBC) be Applied to Thyroid Fine Needle Aspiration Cytology Samples?: Comparative Analysis of Conventional and LBC Smears

Context:

Liquid-based cytology (LBC) is a cyto-preparatory technique that may be applied to fine-needle aspiration (FNA) samples. However, its efficacy over conventional smears (CS) in thyroid is controversial.

Aims:

The aim of this study was to compare CS versus LBC (SurePath, BD) preparations in thyroid FNA samples for diagnostic efficacy.

Settings and Design:

Prospective case-control study using split sample analysis in 200 non-consecutive cases of thyroid FNA reported as per the Bethesda system.

Methods and Material:

Detailed cytomorphological features were evaluated in CS and LBC preparations. Cellularity was scored as 0–3. Based on diagnostic efficacy, they were categorized into three groups:(i) CS and LBC equivalent for diagnosis, (ii) CS better than LBC, and (iii) LBC better than CS for providing the diagnosis.

Statistical Analysis Used:

Paired t test for cellularity scores and descriptive for diagnostic efficacy.

Results:

There were 7 unsatisfactory, 118 benign, 10 atypia or follicular lesion of undetermined significance, 25 follicular neoplasms, 6 suspicious for malignancy, and 34 malignant thyroid FNA cases based on routine conventional smears. Cellularity of conventional smears was significantly higher than paired LBC smears (paired t test, P < 0.005). Comparison of overall diagnostic efficacy showed that LBC and CS were equivalent in 59% of cases; CS was superior to LBC in 37% cases and LBC was better than CS in 4% cases only. LBC smears showed higher unsatisfactory rate as compared to CS (18% vs. 3.5%). In category 2, the two techniques were equivalent in 87% of cases. In categories 4 and 6, CS were superior to LBC.

Conclusions:

In thyroid FNA cases, conventional smears are superior to LBC preparation in terms of cellularity and diagnostic efficacy and hence, LBC preparations should not replace conventional smears for making a routine cytomorphological diagnosis.

Comparison of Diagnostic Rates and Concordance with Subsequent Surgical Resections between Conventional Smear and ThinPrep Preparations versus ThinPrep Only in Thyroid Fine Needle Aspiration (T-FNA) Specimens

BACKGROUND

Thyroid fine needle aspiration (T-FNA) is a mainstay in management of thyroid nodules. However, the preparation of T-FNA specimens varies across institutions. Prior studies have compared diagnostic rates between different specimen preparations of T-FNA specimens and their associated advantages and disadvantages. However, few have compared the rates of all diagnostic categories of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) between liquid-based preparations (LBPs) and a combination of LBP and conventional smear (CS) preparations. Our study compares TBSRTC diagnostic rates between these 2 cohorts and correlates cytologic diagnoses with subsequent thyroid resections to evaluate rates of neoplasia (RON) and malignancy (ROM).

METHODS

584 consecutive thyroid FNA specimens were collected and stratified by preparation type (ThinPrep [TP] vs. CS &amp; TP). Diagnostic rates for each TBSRTC diagnostic category were calculated. The institution's electronic medical records database was searched for histologic diagnoses of previously sampled thyroid nodules to evaluate the RON and ROM.

RESULTS

Of 584 thyroid FNA specimens, 73 (12.5%) and 511 (87.5%) were evaluated by TP only and CS &amp; TP, respectively, reflecting the predominance of rapid on-site evaluation (ROSE) with CS for T-FNAs at our institution. Of the TP only and CS &amp; TP cohorts, 29 (39.7%) and 98 (19.2%) had subsequent resections, respectively. The frequency of non-diagnostic cases was lower in the CS &amp; TP cohort (12.7% vs. 26%). While the diagnostic rate of follicular lesion of undetermined significance was similar for both cohorts, SFN categorization was only utilized in the CS &amp; TP cohort (1.5% vs. 0%). Although RON and ROM were similar between cohorts in many of the TBSRTC categories, there was a higher RON associated with non-diagnostic specimens in the TP only cohort when the denominator included all non-diagnostic cases.

CONCLUSION

The combination of CS and LBP may potentially decrease the non-diagnostic rate of T-FNA specimens as well as the number of passes required for diagnosis, particularly with ROSE. Evaluation of morphologic features highlighted in conventional smears may facilitate diagnostic categorization in the "suspicious for follicular neoplasm" category.

Clinicopathological Study of 117 Body Fluids: Comparison of Conventional Smear and Cell Block Technique

BACKGROUND

Cell block method (CB) has emerged as an invaluable tool for diagnosis of effusions. It can help overcome the problems faced by conventional smear (CS) by differentiating between reactive, inflammatory and malignant cells. The aim of the study is to compare and correlate the CB diagnosis with the CS findings of various pathological conditions including malignancy.

MATERIALS AND METHODS

Two years prospective cross-sectional study of 117 fluids received for routine examination and/or for cytology was conducted. CS as well as CB was simultaneously prepared from the fluid and the results were correlated and tabulated for statistical analysis.

RESULTS

Mean age of presentation was 43±21.1 years and male: female ratio was 1.3:1. Ascitic fluid (46.2%) was the most common followed by pleural (40.2%). Among malignancies, primary ovarian and lung carcinoma were the most common to present with malignant ascites (33.3%) and pleural effusion (66.7%) respectively. Six suspicious for malignancy on CS were provided a definitive diagnosis of malignancy on CB. Overall, CB increased the yield of malignancy by 8.3%. The agreement between CB and CS for malignant effusions and suspicious for malignancy were 41.7% and 14.3% respectively. Sensitivity of CS method when compared to CB, for malignant peritoneal and pleural effusions was 90% and 75% respectively while the specificity was 68% and 79% respectively.

CONCLUSION

CB has a better diagnostic yield of malignancy and helps in providing a definitive diagnosis for cases that are suspicious for malignancy on CS. Hence, CB should be routinely employed along with CS for all effusions.

Comparative Analysis of Liquid based and Conventional Cytology Smears in Fine Needle Aspirates from Breast Lesions

Context

Liquid-based cytology (LBC) is being extensively used for the evaluation of both gynecological and non-gynecological specimens. Suspension of cells in monolayer makes better morphological assessment possible. Along with this, inherent morphological changes such as altered, reduced, or lost background material, fragmented cell clusters, smaller cell size, nucleolar prominence, etc., need to be considered.

Aim

Present study was aimed at comparative evaluation of utility of LBC versus conventional smear (CS) in assessing breast lesions and whether it can be used as an alternative to conventional preparation.

Settings and Design

Present study was a prospective study in which 75 cases of breast fine-needle aspiration cytology from patients with palpable breast lumps constituted the study group.

Material and Methods

The first pass was used for CS and LBC; a second pass was given. The representative CS and LBC smears were compared using several criteria.

Statistics

Each feature was scored individually and evaluated statistically using Wilcoxon's signed rank test on the SPSS program.

Results

A statistically significant difference was found in informative background and background blood-debris, whereas the difference was not statistically significant in other features such as cellularity, cytoarchitectural pattern, presence of monolayer, and nuclear and cytoplasmic details.

Conclusion

LBC is a promising technique in the field of cytology. It has the potential to decrease the number of slides screened per case and decrease the turn-around-time.

Comparison of Unsatisfactory Samples from Conventional Smear versus Liquid-Based Cytology in Uterine Cervical Cancer Screening Test

BACKGROUND

Cervical cytology for uterine cervical cancer screening has transitioned from conventional smear (CS) to liquid-based cytology (LBC), which has many advantages. The aim of this study was to compare the proportion of unsatisfactory specimens from CS versus LBC at multiple institutions including general hospitals and commercial laboratories.

METHODS

Each participating institution provided a minimum of 500 Papanicolaou (Pap) test results for analysis. Pap tests were classified according to the participating institution (commercial laboratory or general hospital) and the processing method (CS, ThinPrep, SurePath, or CellPrep). The causes of unsatisfactory results were classified as technical problems, scant cellularity, or complete obscuring factors.

RESULTS

A total of 38,956 Pap test results from eight general hospitals and three commercial laboratories were analyzed. The mean unsatisfactory rate of LBC was significantly lower than that of CS (1.26% and 3.31%, p = .018). In the LBC method, samples from general hospitals had lower unsatisfactory rates than those from commercial laboratories (0.65% vs 2.89%, p = .006). The reasons for unsatisfactory results were heterogeneous in CS. On the other hand, 66.2% of unsatisfactory results in LBC were due to the scant cellularity.

CONCLUSIONS

Unsatisfactory rate of cervical cancer screening test results varies according to the institution and the processing method. LBC has a significantly lower unsatisfactory rate than CS.

Comparison of Unsatisfactory Samples from Conventional Smear versus Liquid-Based Cytology in Uterine Cervical Cancer Screening Test

BACKGROUND

Cervical cytology for uterine cervical cancer screening has transitioned from conventional smear (CS) to liquid-based cytology (LBC), which has many advantages. The aim of this study was to compare the proportion of unsatisfactory specimens from CS versus LBC at multiple institutions including general hospitals and commercial laboratories.

METHODS

Each participating institution provided a minimum of 500 Papanicolaou (Pap) test results for analysis. Pap tests were classified according to the participating institution (commercial laboratory or general hospital) and the processing method (CS, ThinPrep, SurePath, or CellPrep). The causes of unsatisfactory results were classified as technical problems, scant cellularity, or complete obscuring factors.

RESULTS

A total of 38,956 Pap test results from eight general hospitals and three commercial laboratories were analyzed. The mean unsatisfactory rate of LBC was significantly lower than that of CS (1.26% and 3.31%, p = .018). In the LBC method, samples from general hospitals had lower unsatisfactory rates than those from commercial laboratories (0.65% vs 2.89%, p = .006). The reasons for unsatisfactory results were heterogeneous in CS. On the other hand, 66.2% of unsatisfactory results in LBC were due to the scant cellularity.

CONCLUSIONS

Unsatisfactory rate of cervical cancer screening test results varies according to the institution and the processing method. LBC has a significantly lower unsatisfactory rate than CS.

Combined use of conventional smear and liquid-based preparation versus conventional smear for thyroid fine-needle aspiration

The purpose of the study was to compare the diagnostic utility of the combined conventional smear (CS) and liquid-based preparation (LBP) compared to CS with respect to the non-diagnostic rate, the atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS) rate, and the diagnostic performances for malignancy. This retrospective study was approved by the Institutional Review Board, and the need to obtain informed consent was waived. In our institution, thyroid FNAs were processed with CS before October 2012, and LBP has been used in combination with CS after October 2012. On-site evaluation for the adequacy of CS was not performed. This study included nodules 5 mm or larger with FNAs performed by faculties: 811 nodules in 773 patients for CS, and 926 nodules in 894 patients for combined CS and LBP. Nodules with surgery or either benign or malignancy cytology on initial or repeat FNA were regarded to have the reference standards needed to calculate diagnostic performances. The proportion of Bethesda categories and diagnostic performances were compared between the two groups with z test. The non-diagnostic rate, the AUS or FLUS rate, and the diagnostic performances for malignancy were similar (All P > 0.05). The follicular neoplasm (FN) or suspicious for FN rate decreased from 1.2 to 0.3 % (P = 0.034). The benign rate increased from 51.4 to 57.0 % (P = 0.019). Combined CS and LBP decreased FN or suspicious for FN diagnoses, and increased benign diagnoses compared to CS with comparable non-diagnostic rates and AUS or FLUS rates, and comparable diagnostic performances.

Comparison of diagnostic cytomorphology of atypical squamous cells in liquid-based preparations and conventional smears

Background

The aims of this study were to compare the cytomorphologic features diagnostic of atypical squamous cells (ASC) in liquid-based preparations (LBPs) and conventional Pap (CP) smears and to cytomorphologically assess the performance of the Cell Scan 1500™ in cervical cytology practice.

Methods

Cervicovaginal smears were obtained from 938 women. Two smears were obtained simultaneously from each individual, one for an LBP and the other for a CP smear; the smears were independently examined. ASC was diagnosed in 24 patients, and their samples were cytomorphologically and semiquantitatively analyzed.

Results

A total of 24 of the 938 women (2.6%) were diagnosed with ASC by one or both methods. Results from LBPs and CP smears were in agreement in 13 of 24 cases of ASC diagnosis (absolute direct agreement, 54.2%; k<0.20; p-value from chi-square test=0.085). Diagnostic features of ASC in the LBPs included squamous cell atypia and atypical squamous metaplasia.

Conclusions

The cellular features diagnostic of ASC present in one preparation can manifest themselves differently in the other. Changes in individual cells, particularly nuclear changes, are the most reliable features for diagnosing ASC. The Cell Scan 1500™ processor is more effective at detecting ASC than are CP smears.