Application of liquid-based cytology test of bronchial lavage fluid in lung cancer diagnosis

Clinical values of different specimen preparation methods for the diagnosis of lung cancer by EBUS-TBNA

BACKGROUND AND OBJECTIVE

EBUS-TBNA has emerged as an important minimally invasive procedure for the diagnosis and staging of lung cancer. Our objective was to evaluate the effect of different specimen preparation from aspirates on the diagnosis of lung cancer.

METHODS

181 consecutive patients with known or suspected lung cancer accompanied by hilar / mediastinal lymphadenopathy underwent EBUS-TBNA from January 2019 to December 2022. Specimens obtained by EBUS-TBNA were processed by three methods: Traditional smear cytology of aspirates (TSC), liquid-based cytology of aspirates (LBC) and histopathology of core biopsies.

RESULTS

EBUS-TBNA was performed in 181 patients on 213 lymph nodes, the total positive rate of the combination of three specimen preparation methods was 80.7%. The diagnostic positive rate of histopathology was 72.3%, TSC was 68.1%, and LBC was 65.3%, no significant differences was observed (p = 0.29); however, statistically significant difference was noted between the combination of three preparation methods and any single specimen preparation methods (p = 0.002). The diagnostic sensitivity of histopathology combined with TSC and histopathology combined with LBC were 96.5 and 94.8%, the specificity was 95.0% and 97.5%, the PPV was 98.8% and 99.4%, the NPV was 86.4% and 81.2%, the diagnostic accuracy was 96.2% and 95.3%, respectively; The sensitivity and accuracy of above methods were higher than that of single specimen preparation, but lower than that of combination of three preparation methods.

CONCLUSION

When EBUS-TBNA is used for the diagnosis and staging of lung cancer, histopathology combined with TSC can achieve enough diagnostic efficiency and better cost-effectiveness.

Diagnostic role of liquid-based cytology of bronchial lavage fluid in addition to bronchial brushing specimens in lung cancer

BACKGROUND

Liquid-based cytology (LBC) tests, including the liquid-based thin layer method, have demonstrated the highest potential for reducing false-negatives and improving sample quality.

METHOD

This study aimed to evaluate the diagnostic role of LBC of bronchial brushing specimens in lung cancer. A total of 249 patients were analyzed in our study, involving 155 patients with combined bronchial brushing and bronchoalveolar lavage (BAL) and 94 patients with BAL alone.

RESULTS

The sensitivity in the combined bronchial brushing and BAL group was 61.4% in the diagnosis of lung cancer, which is much higher than with BAL alone. Rates of positive predictive values and negative predictive values in the combined group compared with the BALF alone group were 98.6% vs 100% and 47.6% vs 37.4%, respectively. Sensitivity in the BALF alone group was 12.5% in bronchoscopically invisible pulmonary lesions and as high as 52.1% in the combined group.

CONCLUSION

The results from our study demonstrated that LBC of brushing samples could be used as an important complement of bronchoscopy and could have the potential to be widely applied.

Role of Immunocytochemistry in the Cytological Diagnosis of Pulmonary Tumors

Pulmonary cytology is a challenging diagnostic tool, and it is usually evaluated considering medical history and radiological findings in order to reach an accurate diagnosis. Since the majority of lung cancer patients have an advanced stage at diagnosis, a cytological specimen is frequently the only material available for diagnosis and further prognostic/predictive marker determination. Several types of specimens can be obtained from the respiratory system (including sputum, bronchoalveolar lavage, bronchial brushing, fine needle aspiration, and pleural fluid) with different technical preclinical management protocols and different diagnostic yields. Immunocytochemistry (ICC) has a pivotal role in the determination of diagnostic, prognostic, and predictive markers. Therefore, limited cytology samples are to be used with a cell-sparing approach, to allow both diagnostic ICC evaluation as well as predictive marker assessment by ICC or specific molecular assays. In this review, we describe the most common ICC markers used for the diagnosis and prognostic/predictive characterization of thoracic tumors in different cytological specimens.

Liquid-based and conventional cytology for bronchial washings/bronchoalveolar lavages in the diagnosis of malignancy - An institutional experience

Background:

Liquid-based cytology (LBC) has been developed as an alternative for conventional cytology (CC) in cervical smears. It is now increasingly being used all over the world for cervical cancer screening. However, its role and diagnostic accuracy in bronchial wash (BW)/bronchoalveolar lavage (BAL) specimens remains undetermined.

Aims:

To assess and compare the diagnostic performance and accuracy of LBC with CC for detecting malignancy in bronchial specimens.

Settings and Design:

This was a retrospective analytical hospital-based study.

Materials and Methods:

Bronchial specimens (BW/BAL) received over a period of 4.5 years were reviewed. The samples were processed by CC from June 2010 to September 2012 (2.25 years) and by LBC from October 2012 to December 2014 (2.25 years). Data were retrieved from the records of cytology laboratory and compared among both the groups. Detection rate for histologically or cytologically verified samples was calculated.

Results:

A total of 559 cases verified by histological and cytological follow-up were evaluated. These included 247 CC cases and 312 LBC cases. The positive diagnostic rate for malignancy in CC was 28.6% whereas that for LBC was 32.9%. The negative diagnostic rates were 66.5% and 66.3% for CC and LBC, respectively. However, unsatisfactory rates had shown a good reduction from 4.4% in CC to 0.6% after LBC introduction. The smears showed more homogeneous distribution of cells with elimination of obscuring factors such as blood, inflammation, and mucus.

Conclusions:

The diagnostic accuracy of LBC was slightly better than CC. The unsatisfactory rates showed reduction in LBC preparation. Thus, LBC is a viable alternative to CC and has the advantages of standardization of preparation with decrease in unsatisfactory rates.