Fine needle aspiration cytology of cervical lymph nodes: Comparison of liquid based cytology (SurePath) and conventional preparation

Advances in diagnostic liquid-based cytology

Liquid-based cytology (LBC) has changed the landscape of gynaecological cytology. A growing demand exists for LBC in diagnostic cytology, particularly for ancillary testing, such as immunocytochemistry and molecular testing. Ancillary testing solely based on conventional preparation (CP) methods remains challenging. Recently, the increased demand for specialist testing and minimally invasive techniques, such as endoscopic ultrasonography fine-needle aspiration, to obtain cellular samples has led to an increasing demand for ancillary testing on cytology LBC supernatant, slides and cell block (CB). This facilitates the diagnosis and prognosis in cytology samples enabling personalized treatment. An understanding of the history and future prospects of LBC is crucial for its application in routine diagnostics by cytopathologists and cytotechnologists. In this review, we initiated an internet search using the keyword 'liquid-based cytology', and we conducted a literature review to discuss the usefulness of combined diagnosis of LBC and CP, immunocytochemistry and molecular testing and assessed the quality of nucleic acids in diagnostic LBC. High-quality and cell-rich diagnostic LBC surpassed the CP method alone in terms of reliability and versatility of ancillary testing in cytological diagnosis. Conclusively, diagnostic LBC lends itself to various new technologies and is expected to continue evolving with innovations in the future.

Diagnostic value of liquid-based cytology test in intrathoracic lymph nodes and lung lesions sampled by endobronchial ultrasonography-transbronchial needle aspiration

BACKGROUNDS

Liquid-based cytology (LBC) has begun to be used in non-gynecological samples such as endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). This study aims to investigate the diagnostic value of LBC in intrathoracic lymph nodes and lung lesions sampled with EBUS-TBNA.

METHODS

In total, 174 cases that underwent EBUS-TBNA between July 2020 and February 2021 were included (75 and 99 cases were prepared using conventional and LBC methods, respectively). The two groups were compared in terms of diagnostic categories, number of slides, cell blocks, slides per location, locations sampled, immunohistochemical studies, sensitivity, specificity, and diagnostic accuracy.

RESULTS

The percentages of malignant, suspicious for malignancy, benign, and non-diagnostic (ND) cases were 51.8%, 1.1%, 39.6%, and 7.5%, respectively. The LBC and conventional group (CG) had similar rates in the diagnostic categories, except for ND (3.0% and 13.3%, respectively). The sensitivity of LBC and CG were 90.4% and 85.7%, respectively. There were no differences in the specificity and diagnostic accuracy between groups. There was a statistically significant difference between groups in terms of the number of slides, number of slides per location, number of cell blocks, and locations sampled (p < .001, p < .001, p < .05, p < .05).

CONCLUSION

The LBC technique can be used for samples taken with EBUS-TBNA. Rapid fixation and the absence of artificial problems greatly reduce the rate of ND samples in LBC slides. Other important advantages are a lower number of slides to examine and a greater number of cell blocks.