Overview of nongynecological samples prepared with liquid-based cytology medium

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.

Cytomorphological comparison of ThinPrep and SurePath liquid-based cytology in thyroid fine-needle aspiration

BACKGROUND

The two widely established systems for liquid-based cytology (LBC), ThinPrep and SurePath, employ different principles. The aim of this study was to compare the cytomorphology of thyroid lesions prepared by the two techniques.

METHODS

We retrospectively reviewed 44 thyroid FNA specimens prepared by LBC, including 20 ThinPrep and 22 SurePath. Cytologic diagnoses were made according to the Bethesda system and cytomorphologic parameters were evaluated.

RESULTS

Acellular smears were significantly frequent in ThinPrep than SurePath (10% vs. 0%). Both techniques produced a clean background, well cell preservation, and not apparent cell shrinkage. ThinPrep showed significantly lower cellularity than SurePath (25% vs. 4.3%). ThinPrep produced considerable flattening and fragmented clusters, while SurePath contained larger clusters in a three-dimensional configuration. Colloid was significantly reduced in amount and fragmented in ThinPrep, and was easily observed in SurePath. In cases of Hashimoto's thyroiditis, ThinPrep produced much less leukocytes in background than SurePath. Aggregates of fibrin and leukocytes were frequently present in 10/16 cases (62.5%) processed by ThinPrep. Air-dry artifact at periphery of the ring was present in 6/16 cases (37.5%) processed by ThinPrep. The nuclear features of papillary carcinoma were similarly evident in both LBC preparations.

CONCLUSION

SurePath seems to be superior to ThinPrep for diagnosing benign entities based on adequate representation of colloid and lymphocytes. The cell quality of both techniques in thyroid FNA was comparable, while each method introduces its own unique cytologic artifacts related to its methodology. We should recognize the cytomorphologic alterations to avoid misinterpretations.

Cytomorphology of pulmonary low-grade fetal adenocarcinoma in bronchial brushing specimen prepared by BD SurePath: A case report and literature review

Low-grade fetal adenocarcinoma (LGFA) of the lung is a rare subtype of lung adenocarcinoma, resembling developing fetal lung in pseudoglandular stage. LGFA is very different to conventional adenocarcinoma. It is more likely to occur in young adults and has favorable prognosis. Reports on the cytology of LGFA are very rare; only 10 cases have been reported previously in the English literature. Our case report adds to the cytological features of this tumor sampled by bronchial brushing and is the first case prepared by the BD SurePath liquid-based cytology. We present a case of 31-year-old male with endobronchial involvement of right bronchus. The cytological features of diagnostic clues for LGFA include three dimensional glandular arrangements of uniform, columnar cells with inconspicuous nucleoli. It is important to recognize this rare and favorable variant of lung adenocarcinoma. In this report, we present the cytological and pathological features of LGFA, along with a literature review.

Evaluation of a Novel Fixative Solution for Liquid-Based Cytology in Diagnostic Cytopathology

Since its introduction in the early 2000s, liquid-based cytology (LBC) has been increasingly used for gynecologic and non-gynecologic cytology, and its multiple advantages have been widely recognized. The aim of this study was to investigate the use of a new fixative and pre-analytical method for morphological diagnosis in cytological samples. In particular, we evaluated the effect of a novel preservative solution on the preparation of diagnostic slides by comparing it with the standard reference used globally in cytology laboratories. This study included both gynecological (n = 139) and non-gynecological (n = 183) samples. Several morphologic variables were then identified and evaluated. Using this approach, we were then able to demonstrate the suitability of the new system, with improved safety, to be integrated within current pathology clinical practice. Overall, using a safer preservative solution, the study shows no statistical difference (and then non-inferiority) in the new fixation protocol compared with the standard reference used in routine practice in terms of diagnostic adequacy, evaluated both in clinically relevant gyn and non-gyn datasets.

Deep Learning-Based Screening of Urothelial Carcinoma in Whole Slide Images of Liquid-Based Cytology Urine Specimens

Urinary cytology is a useful, essential diagnostic method in routine urological clinical practice. Liquid-based cytology (LBC) for urothelial carcinoma screening is commonly used in the routine clinical cytodiagnosis because of its high cellular yields. Since conventional screening processes by cytoscreeners and cytopathologists using microscopes is limited in terms of human resources, it is important to integrate new deep learning methods that can automatically and rapidly diagnose a large amount of specimens without delay. The goal of this study was to investigate the use of deep learning models for the classification of urine LBC whole-slide images (WSIs) into neoplastic and non-neoplastic (negative). We trained deep learning models using 786 WSIs by transfer learning, fully supervised, and weakly supervised learning approaches. We evaluated the trained models on two test sets, one of which was representative of the clinical distribution of neoplastic cases, with a combined total of 750 WSIs, achieving an area under the curve for diagnosis in the range of 0.984-0.990 by the best model, demonstrating the promising potential use of our model for aiding urine cytodiagnostic processes.

Characterizing the Effect of Processing Technique and Solution Type on Cytomorphology Using Liquid-Based Cytology

INTRODUCTION

Liquid-based cytology (LBC) is increasingly used for nongynecologic applications. However, the cytological preparation of LBC specimens is influenced by the processing technique and the preservative used. In this study, the influence of the processing techniques and preservatives on cell morphology was examined mathematically and statistically.

METHODS

Cytological specimens were prepared using the ThinPrep (TP), SurePath (SP), and AutoSmear methods, with 5 different preservative solutions. The cytoplasmic and nuclear areas of Papanicolaou-stained specimens were measured for all samples.

RESULTS

The cytoplasmic and nuclear areas were smaller in cells prepared using the 2 LBC methods, compared to that prepared using the AutoSmear method, irrespective of the preservative used. The cytoplasmic and nuclear areas of cells prepared using the SP method were smaller than those of cells prepared using the TP method, irrespective of the preservative used. There were fewer differences among the cytoplasmic areas of cells prepared with different preservative solutions using the TP method; however, the cytoplasmic areas of cells prepared using the SP method changed with the preservative solution used.

CONCLUSIONS

The most significant difference affecting the cytoplasmic and nuclear areas was the processing technique. The TP method increased the cytoplasmic and nuclear areas, while the methanol-based PreservCyt solution enabled the highest enlargement of the cell. LBC is a superior preparation technique for standardization of the specimens. Our results offer a better understanding of methods suitable for specimen preparation for developing precision AI-based diagnosis in cytology.

Conventional Direct Smear Yields Diagnostic Indicators of Gastric-Type Mucinous Carcinoma Compared with Cytomorphological Features Identified by Liquid-Based Cervical Cytology

INTRODUCTION

Gastric-type mucinous carcinoma (GAS) of the uterine cervix is an adenocarcinoma subtype with a gastric phenotype that poses diagnostic pitfalls in cervical screening cytology because of its blunt morphologic atypia and the limited utility of human papillomavirus testing and ancillary immunochemical staining. Despite the recent widespread uptake of liquid-based cytology (LBC) systems, the cytomorphological features of GAS in LBC samples and the differential features between GAS and usual-type endocervical adenocarcinoma (UEA) remain unclear.

METHODS

Eight GAS cases, all of which were surgically treated following histological confirmation, were examined. Direct Papanicolaou-stained smears and LBC samples were reviewed and compared with 10 UEA cases as controls. Featured cytomorphological findings were as follows: background (mucinous, inflammatory, or necrotic), cell crowding (size of neoplastic cell clusters), cytoplasm (golden mucin and cell border), and nuclei (nuclear chromatin and nucleoli).

RESULTS

Of 18 adenocarcinomas, 16 were detected against a non-mucinous background in LBC samples, most of which were accompanied by mild to moderate inflammation. Clusters comprising >300 neoplastic cells were identified in both GAS and UEA in conventional smears (CSs), while no LBC samples harboured clusters as large as these. Cell borders of GAS were more distinct than those of UEA in CSs (p < 0.001), although fewer populations of neoplastic clusters revealed distinct cell borders in both GAS and UEA in LBC samples. Three of 8 and 2 of 8 GAS cases had golden mucin in CSs and in LBC samples, respectively, which was not detected in UEA at all. Nucleoli against fine nuclear chromatin were more pronounced in GAS than in UEA on CS (p = 0.03), although the difference between GAS and UEA was not apparent in LBC samples.

DISCUSSION/CONCLUSION

This study demonstrated that the diagnostic clues to detect GAS using the conventional approach, namely distinct cell borders and prominent nucleoli, are not useful for excluding UEA in LBC samples. Conventional cervical smears may indicate a diagnosis of GAS; however, specific high-risk HPV detection approaches, such as HPV test or immunocytochemical p16/Ki-67 dual staining, are desirable to differentiate GAS from UEA in the setting of LBC with ambiguous cytomorphological features.

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

BACKGROUND

Fine needle aspiration cytology (FNAC) is the first diagnostic step in patient with cervical lymphadenopathy because of its simplicity, safety and early availability of the results. Liquid-based cytology (LBC) is an alternative processing method which is used for both gynecological and nongynecological samples. Literature reviewed show few studies comparing LBC with conventional preparation (CP).

AIM

The present study was undertaken to evaluate the efficacy of LBC and comparison of LBC and CP in cervical lymphadenopathy.

MATERIALS AND METHODS

In this prospective study, a total of 75 cases of FNAC with cervical lymphadenopathy were included. The first pass was used for CP followed by LBC with the use of SurePath (SP) technique. Both the smears were compared for cellularity, background containing blood, cell debris, lymphoglandular bodies, stromal fragments, cytoarchitectural pattern, etc., by semiquantitative scoring system.

RESULTS

There was no statistical difference in the cellularity, cell architecture, and monolayer cells (P > .05). On the basis of background containing blood, cell debris, lympho-glandular bodies, stromal fragments (P < .001), nuclear, and cytoplasmic details (P < .05), LBC was found to be superior to CP.

CONCLUSION

LBC is a relatively simple technique and superior to CP in respect of better nuclear and cytoplasmic details with loss of background blood and debris. It has a diagnostic accuracy equivalent to that of CP. However, use of both LBC and CP can result in better diagnostic accuracy.

Liquid-based cytology versus conventional cytology in fine-needle aspirates of salivary gland neoplasms

Background

Liquid-based cytology (LBC) is a method of retrieving and processing of cytological material for the assessment of both gynecological and nongynecological cases introduced in 1996. Mostly conventional smears (CS) are prepared in Indian scenario; however, due to increasing popularity of LBC in nongynecology specimens, LBC is also used in few centers for diagnosing salivary gland neoplasm.

Aim

The aim of this study is to compare CS and LBC in fine-needle aspiration cytology (FNAC) of the salivary gland neoplasms in terms of cytomorphological details, adequacy, ease of interpretation, pitfalls, and diagnostic efficiency.

Materials and Methods

We conducted a prospective, observational, comparative study which included 64 salivary gland neoplasms. Both CS and LBC (SurePath) were prepared as per standard protocols and examined.

Results and Conclusion

In our study, specificity and positive predictive value of both the techniques (conventional and LBC) were found to be 100%. Sensitivity of both the techniques was found to be similar (66.7%). Negative predictive value and diagnostic accuracy of conventional technique were found to be almost similar to that of LBC technique (97.6% vs. 97.2% and 97.7% vs. 97.4%). In terms of adequacy and cellularity, CSs were better than LBC. Ease of interpretation was better with CSs due to abundant chondromyxoid stroma, an important clue in the diagnosis of pleomorphic adenoma. Nuclear details and background were better in LBC as compared to CS. Hence, we conclude that in salivary gland FNAC, both CS and LBC have similar diagnostic efficiency. however, interpretation of conventional smears is easier than Liquid Based Cytology especially in cases of pleomorphic adenoma. However, some advantages of LBC in respect to conventional cytology, with better-preserved morphology obtained from LBC becomes furthermore obligatory.

Pathological and Molecular Aspects to Improve Endoscopic Ultrasonography-Guided Fine-Needle Aspiration From Solid Pancreatic Lesions

Endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) has been applied to pancreatic lesions since the 1990s, and its use is now widespread. Improvements in endoscopic devices and sampling techniques have resulted in excellent diagnostic ability for solid pancreatic lesions. However, clinical improvements alone are not responsible for it; pathological aspects have also played important roles. Rapid on-site evaluation minimizes endoscopic procedures, although its value at improving the diagnostic ratio is still debated. Diagnostic efficacy differs by sample preparations (direct smear, cytospin, liquid-based cytology, cell block, and biopsy) and by staining methods (Papanicoloau, Diff-Quik, hematoxylin-eosin, and Giemsa). Several immunocytochemistry protocols aid in diagnosing epithelial components with cytological atypia and in differentiating various tumor types. One cytopathology diagnostic system is telecytology, which uses transmitted digital images and enables real-time diagnosis of EUS-FNA samples by expert cytologists at remote locations. However, EUS-FNA samples are useful for more than just diagnoses, as molecular analysis of these samples allows the identification of prognostic markers, such as genetic alterations in K-ras and EGFR. Expression of drug-metabolizing enzymes, human equilibrative nucleoside transporter 1, correlates with the response to gemcitabine-based chemotherapy. These pathology efforts have enhanced the diagnostic efficacy of EUS-FNA, thereby leading to better outcomes for patients with pancreatic diseases.

The diagnostic and prognostic role of liquid-based cytology: are we ready to monitor therapy and resistance?

Here, we evaluate the diagnostic and prognostic role of liquid-based cytology (LBC) in different body lesions, including thyroid, lung, effusions and malignant breast lesions. LBC has gained consensus after being applied to both non-gynecologic and fine-needle aspiration cytology. Although some remain sceptical regarding the diagnostic efficacy of LBC, mainly when used alone, in recent years, good results have been obtained as long as it showed a high diagnostic accuracy. Here, we discuss the additional possibility of storing material for the application of ancillary techniques (immunocytochemistry-molecular analysis) with several diagnostic and prognostic advantages, which may pave the way for the challenging evaluation of both monitoring responses to treatment and resistance to targeted therapies in thyroid, lung, breast carcinoma or malignant effusions. Furthermore, it provides the use of several molecular spots as specific targets for personalized therapy.

Direct comparison of liquid-based and smear-based cytology with and without rapid on-site evaluation for fine needle aspirates of thoracic tumors

BACKGROUND

Liquid-based cytology (LBC) and rapid on-site evaluation (ROSE) are proposed to improve the quality of fine needle aspirates (FNA) and their diagnostic yield compared with conventional smear cytology (CSC). This prospective study directly compared outcomes of sonar-guided FNA of thoracic tumors supported by LBC, CSC, or CSC with ROSE.

METHODS

Three aspirates each for both LBC and CSC with separate 22G spinal needles in a randomized, alternating sequence during 64 transthoracic FNA of thoracic tumors were collected. Smears were prepared by cytology staff on site but evaluated with ROSE only when all six samples had been collected. If no diagnostic material was found on the first three CSC additional needle passes guided by ROSE were performed.

RESULTS

Final diagnoses were non-small cell lung cancer in 50 (78.1%), small cell lung cancer in 11 (17.2%), mesothelioma in 1 (1.6%), and inflammation in 2 cases (3.1%), respectively. LBC and CSC were diagnostic in 42 (65.6%) and 49 (76.6%) cases, respectively (P = 0.039), with both methods diagnostic in 41 cases (64.1%). Fifteen cases (23.4%) remained undiagnosed following three passes for CSC but 9 (14.1%) of these were diagnosed using FNA and ROSE with a total yield of 58 cases (90.6%; P < 0.001).

CONCLUSION

The diagnostic yield of transthoracic FNA submitted for LBC is significantly lower than with CSC when slides are prepared professionally. ROSE significantly increases the yield of transthoracic FNA.

Utility of manual liquid-based cytology and conventional smears in the evaluation of various fine-needle aspiration samples

BACKGROUND

Liquid-based cytology (LBC) preparation is a way to improve and refine the fine-needle aspiration (FNA) samples. There are a few studies comparing LBC with conventional smear (CS).

AIM

The present study was undertaken to evaluate the utility of manual LBC (MLBC) and CS preparations in various FNA samples.

MATERIALS AND METHODS

In this cross-sectional study, a total of 100 FNA samples from various anatomical sites were evaluated using MLBC and CS preparations. Cellularity, blood, informative background, monolayers, cell architecture, cytoplasmic, and nuclear preservation were compared with MLBC and CS preparations by Wilcoxon signed rank test. P < 0.05 is considered statistically significant.

RESULTS

MLBC preparations were superior to CS preparations in view of absence of blood and debris (P = 0.001), presence of monolayers (P < 0.001), and preservation of cytoplasmic (P = 0.001) and nuclear details (P = 0.001). However, no statistically significant differences were found between MLBC and CS preparations with regard to cellularity (P = 0.157), informative background (P = 0.083), and architecture (P = 0.739).

CONCLUSION

MLBC preparations in FNAC are a safe, easy, and less time-consuming procedure, and it may have promising diagnostic value in the evaluation of FNA samples from various anatomical sites. However, the use of both MLBC and CS preparations is recommended to achieve optimal diagnostic yield.

Cytomorphologic features and differential diagnosis of neoplasms with small cell features in liquid-based urinary tract cytologic specimens

INTRODUCTION

Urinary tract cytology (UTCy) allows the accurate diagnosis of high grade urothelial carcinoma. Rare malignancies characterized by the presence of small cells may be more difficult to recognize, however. The aim of this study was to review our experience with liquid-based (ThinPrep) UTCy specimens showing small atypical cells and characterize their cytomorphology, potential differences from previously reported morphologic features, and discuss their differential diagnostic considerations.

MATERIALS AND METHODS

Among 18,859 UTCy specimens reviewed during a 13-year period (2001-2012), we identified 13 cases corresponding to surgical pathology specimens diagnosed as small cell carcinoma (6), melanoma (3), lymphoma (3), and leukemic involvement of the urinary tract (1). We recorded the original diagnoses made on these cases and 10 cytomorphologic features that could aid in their diagnosis.

RESULTS

We identified 13 cases in UTCy of 7 men and 6 women; 11 of which were diagnosed as positive or suspicious for malignancy. In 8 out of 13 cases (62%) the type of malignancy was correctly reported. Of the 10 recorded features, cellular clustering and nuclear molding were seen only in small cell carcinoma, whereas prominent nucleoli and an inflammatory background or diathesis were noted in lymphoma and melanoma cases. Intracellular pigment and multinucleation were recorded in melanoma cases.

CONCLUSION

The presence of small atypical cells in liquid-based UTCy should raise the suspicion of underlying malignancy involving the urinary tract. Cell clustering, nuclear molding, and hyperchromasia are helpful hints for the diagnosis of small cell carcinoma and the presence of small atypical cells with prominent nucleoli raises the possibility of lymphoma or melanoma.