The potential of liquid-based cytology in lymph node cytological evaluation: the role of morphology and the aid of ancillary techniques

Comparison of liquid based cytology and conventional smears on lymph node aspirates: A cytomorphological study

Objective

In an era of minimally invasive and rapid diagnostic technologies, fine-needle aspiration cytology (FNAC) is most useful when it comes to patients with lymphadenopathies especially of the cervical region. Liquid-based cytology (LBC) is an alternative processing method which is used for both gynecological and non-gynecological samples. Because of the remarkable advantages of LBC smears in gynecological samples, nowadays, many studies have been done to assess its utility in various other lesions. Hereby, with the help of this study, we would like to evaluate the efficiency of LBC smears in comparison to conventional FNAC smears conventional smears (CS) on lymph node aspirates.

Material and Methods

A retrospective study was done over a 1-year period in which 253 cases of lymph node aspirates were included in the study. The slides were prepared using standard conventional and LBC techniques and compared for adequacy, cellularity, cell architecture, necrosis, background debris, presence of cells in monolayer sheets, and nuclear/cytoplasmic details.

Results

Of the total 253 cases, 171 (67.6%) were and 67 (26.5%) were diagnosed as non-neoplastic and malignant, respectively. Although the LBC smears were useful in the diagnosis of malignant cases, they did pose some challenges especially in the non-neoplastic lymph node aspirates due to loss of the background necrosis. In addition, the cellular yield in LBC smears was low in comparison to CS.

Conclusion

LBC smears from lymph node aspirates results in better diagnostic accuracy for malignant cases due to better cellular and nuclear details. However, for non-neoplastic etiology, it should not be considered better than CS as loss of the background necrosis and inflammation may result in an incorrect diagnosis.

Diagnostic accuracy of Thinprep® in cervical lymph node aspiration: Assessment according to the Sydney system

BACKGROUND

Fine-needle aspiration cytology (FNAC) is a reliable technique that has been used for many years in lymphadenopathy diagnosis. Although conventional smear is the standard approach in FNAC, liquid-based cytology (LBC) is accepted as an alternative method. Reporting standardization is a significant gap in fine-needle aspiration cytology, leading to failure in pathologist-clinician dialog and interobserver variability. In 2020, an expert panel proposed the Sydney system for classifying and reporting lymph node aspiration cytology. This study aimed to evaluate the diagnostic accuracy of LBC in lymph node aspiration cytology under the guidance of the Sydney system.

METHODS

Five hundred-four LBC samples were reevaluated and classified according to the Sydney system. Of these, n = 24 were categorized as L1-inadequate/non-diagnostic, n = 283 as L2-benign, n = 36 as L3- atypical cells of undetermined significance/atypical lymphoid cells of uncertain significance (AUS/ALUS), n = 48 as L4-suspicious, and n = 113 as L5-malignant. Four hundred-one samples were histopathologically confirmed. The diagnostic accuracy of LBC and the risk of malignancy for each Sydney category were calculated.

RESULTS

The results were as follows: sensitivity 98.97%; specificity 98.60%; positive predictive value 94.80%; negative predictive value 99.29%; and overall diagnostic accuracy 98.75%. The ROM was 16.6% for L1, 0.7% for L2, 88.8% for L3, and 100% for L4 and L5.

CONCLUSION

LBC is suitable for use in lymph node aspiration under the guidance of the Sydney system and has high diagnostic accuracy. Future comprehensive studies will increase the applicability of the Sydney system and minimize interobserver variability.

A comparative study of two liquid-based preparation methods: membrane-based and sedimentation in fine needle aspiration cytology diagnosis in thyroid nodules

Background

As thyroid fine needle aspiration (FNA) shows a certain limitation in the diagnosis of conventional smears, novel approaches like liquid-based cytology (LBC) have been gradually applied recently. Studies have shown the difference between the conventional smears (CSs) and liquid-based smears on fine needle aspiration cytology (FNAC) diagnosis, but the impacts of different liquid-based preparation (LBP) methods, including membrane-based and sedimentation, on diagnosis are still not clear. In this study, the effects of liquid-based smears prepared by different methods on the cytological interpretation were studied.

Methods

A total of 221 thyroid liquid-based FNAC cases from January 2017 to October 2018 were collected. We retrospectively studied and compared the effects of the membrane-based and sedimentation LBP methods through The Bethesda System for Reporting Thyroid Cytopathology (TBS) diagnosis and risk of malignancy assessment. Besides, we made an evaluation on the diagnostic differences in the effects of different preparation methods on the cell morphology and tissue structure of papillary thyroid carcinoma (PTC) for more accurate FNAC diagnosis.

Results

Among the 221 cases reviewed, membrane-based method was applied in 153 cases and sedimentation in 68 cases. According to the diagnostic criteria of 2017 TBS, TBSVI and TBSV thyroid could be cytologically diagnosed by membrane-based (49.0% (75/153) and 25.5% (39/153)) and sedimentation (52.9(36/68) and 25(17/68)) methods, and both were confirmed as PTC through histopathological diagnosis after operation, with the malignancy degree as high as 100%. In addition, of the 30 cases that were diagnosed as TBSIII thyroid nodules with the membrane-based method, 15 cases were pathologically malignant after an operation, with the malignancy degree of 50% (15/30), while that in 11 cases using the sedimentation method was 45.4% (5/11). PTC could be detected in both the TBSIV and TBSII thyroid nodules diagnosed by membrane-based method, with the sensitivity of 87.0% (114/131) lower than that by sedimentation method (91.4% (53/58)), showing the lower consistency with the histopathological result (K = 0.635 vs K = 0.757). Among the membrane-based smears, 23.5% (36/153) had fewer follicular epithelial cells, 55.6% (20/36) of which were considered to be suspicious for PTC from cell karyotype and tissue arrangement. While among the sedimentation smears, 16.2% (11/68) had fewer follicular epithelial cells, and 63.6% (7/11) was suspicious for PTC. In 72.5% (95/131) membrane-based smears of PTC, the papillary and swirling structures were not obvious, showing as crowded syncytial cell masses, while in 55.2% (32/58) sedimentation smears, both structures were visible with obvious three-dimensional papillary structure, and the fibrovascular axis still remained.

Conclusion

LBP technique is feasible for FNAC diagnosis, and the sedimentation shows more advantages, like higher PTC detection rate and good consistency with postoperative histopathological diagnosis. A clear understanding of the subtle differences in the effects of membrane-based and sedimentation methods on the cell morphology and tissue structure could be conducive to the definitive diagnosis of PTC before operation.

To Obtain More With Less: Cytologic Samples With Ancillary Molecular Techniques-The Useful Role of Liquid-Based Cytology

CONTEXT

- Fine-needle aspiration cytology has been increasingly used as the first tool in the evaluation of several diseases. Although cytology has a relevant role in the discrimination between benign and malignant lesions, conventional slides cannot lead to 100% conclusive results. It was hoped that the introduction of liquid-based cytology (LBC) would improve the efficacy of cytology through standardization, quality improvement, and the possibility of carrying out ancillary techniques on the residual stored material. In recent decades, the application of genomic alterations has been studied on cytologic samples with feasible and reliable results. The molecular analysis offers a powerful aid to define the best clinical or surgical approaches and follow-up for patients. In recent years, the application of different ancillary techniques has been carried out on conventional slides even though LBC represents a useful additional and alternative method for molecular testing.

OBJECTIVE

- To demonstrate the relevance of LBC as a valid aid to overcoming the difficulties encountered in the application of ancillary techniques on conventional slides.

DATA SOURCES

- We examined and reviewed our experience with the application of ancillary techniques on LBC performed on different body sites.

CONCLUSIONS

- We emphasize that LBC achieves significant and accurate results. It represents a valid method for cytologic evaluation and it provides highly reproducible and informative molecular yields.

Molecular Testing in EBUS-TBNA Specimens of Lung Adenocarcinoma: A Study of Concordance Between Cell Block Method and Liquid-Based Cytology in Appraising Sample Cellularity and EGFR Mutations

PURPOSE

Cytological endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) specimens of mediastinal lymph node metastasis are frequently used to perform concomitant diagnosis, staging and genetic testing in non-small-cell lung cancer (NSCLC). The purposes of this single-center retrospective study were to evaluate EBUS-TBNA samples' adequacy for molecular testing of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK), and to analyze the concordance between the cell block method and liquid-based cytology (LBC) in appraising the sample cellularity and in detecting EGFR mutation.

MATERIALS AND METHODS

We retrospectively examined 82 patients who underwent EBUS-TBNA from October 2012 to September 2015 and received a confirmed diagnosis of lymph node metastasis of lung adenocarcinoma. Each sample was processed using both cell block and LBC to carry out DNA analysis (adequacy criterion: tumor cell percentage > 25%) and EGFR mutation testing.

RESULTS

Fifty-four patients were male, 66 were current or former-smokers, and the median age was 67 years. The median size of sampled lymph nodes was 14.8 mm. Seventy-one and 66 samples were adequate to perform cell block and LBC, respectively. The κ-statistic (0.78) showed an excellent concordance. EGFR mutation was detected in eight patients using cell block and in seven using LBC, with a simple percentage agreement of 87.5%. ALK translocation was found in two patients.

CONCLUSIONS

This study demonstrates the feasibility of EGFR mutation analysis with both cell block and LBC, with an excellent concordance between the two methods. Considering that the majority of advanced NSCLCs are diagnosed on cytology specimens, LBC is feasible and needs to be implemented for ancillary tests (immunocytochemistry, molecular analysis).

Diagnostic value of liquid-based cytology with fine needle aspiration specimens for cervical lymphadenopathy

Background

Cervical lymphadenopathy is a symptom that is frequently seen among outpatients, and it is important to differentiate malignant lesions from reactive lymphoid hyperplasia. Fine needle aspiration (FNA) cytology has been widely used for the diagnosis of cervical lymphadenopathy. However, some limitations of the diagnostic accuracy using conventional smear (CS) cytology have been pointed out. The diagnostic value of liquid‐based cytology (LBC) with FNA specimens has not yet been fully proven.

Methods

Forty‐two patients with cervical lymphadenopathy who underwent FNA with CS cytology from 2007 to 2011 and 123 patients who underwent FNA with LBC utilizing LBCPREP2™ from 2011 to 2015 were studied. Diagnostic values were compared between the CS and the LBC groups.

Results

Of the total 165 patients representing the combined CS and LBC groups, 81 (49.1%) were diagnosed as benign lymph node and 84 (50.9%) were malignant diseases including 37 (22.4%) of metastatic carcinoma except for thyroid carcinoma, 30 (18.2%) of metastatic thyroid carcinoma, and 17 (10.3%) of malignant lymphoma. The overall statistical values including sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the CS were 75%, 100%, 100%, 78.9%, and 87.1%, respectively, whereas those values for LBC were 91.2%, 100%, 100%, 90.7%, and 95.3%, respectively. The sensitivity of LBC for malignant diseases tended to be higher than that of CS cytology (p = 0.081).

Conclusion

LBC with FNA specimens from cervical lymphadenopathy is a useful and reliable method for the diagnosis of malignant diseases, especially of metastatic carcinomas, due to its increased sensitivity compared with CS cytology. Diagn. Cytopathol. 2016;44:169–176. © 2016 Wiley Periodicals, Inc.