Rapid cell blocks improve accuracy of breast FNAs beyond that provided by conventional cell blocks regardless of immediate adequacy evaluation

Contemporary art of cell-block preparation: Overview

Cell blocks (CBs) are paraffin-embedded versions of cytology specimens. These versions are contrasted with tissues made from surgical pathology specimens of formalin-fixed paraffin-embedded (FFPE) tissue. CBs enable various elective ancillary studies of a range of specimens. These studies include the potential to perform molecular tests with the enhanced cytopathological interpretation. CBs are increasingly reported in cytology specimens. The enhanced role of CBs incorporates additives with new markers for immunohistochemistry (IHC), including the multicolored approach to IHC, and the subtractive coordinate immunoreactivity pattern. Even when archived material is retrospectively retrieved, CBs are a major tissue source for many supplementary studies. The CBs have been qualitatively and quantitatively improved. CBs are significant since they have increased molecular markers standardized on FFPE tissue. High-quality CBs can serve as useful additions to cytological smear preparations and touch imprint cytology. Most cytological specimens, such as fine-needle aspirations, cavitary effusion, washings, brushings, and gynecological and non-gynecological liquid specimens, may be used to produce CBs. This review deals with the CB-making process and discusses various historical limitations with an emphasis on recent advances.

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.

Tumor Cell Representation by an Improvised Technique of Fine-Needle Aspiration Specimen Acquisition and Cell Block Preparation: Our Experience in Lung Cancer Cases in a Peripheral Center of Eastern India

Background

Being a minimally invasive diagnostic technique, Fine-Needle Aspiration Cytology (FNAC) has become the first-line test and corresponding aspirated material has become the target specimen for diagnosis and ancillary tests in lung carcinoma. Although the role of Cell Blocks (CBs) in diagnosis and in ancillary testing is well recognized in literature, limited attention has been paid to specimen procurement and triage in the preparation of CBs. In the present scenario, CBs are not consistently optimal because of its low cellularity.

Aims

This study is aimed to describe an improvised technique of specimen acquisition and cell block preparation in CT-guided FNACs of lung carcinoma cases in a resource-constrained center and to assess its efficacy for optimal representation of cellularity, morphology, and architecture.

Materials and Methods

Total 85 lung carcinoma cases undergoing CT-guided FNAC in our center from February 2017 to January 2018 were included in this study. 4 to 5 direct smears and subsequent CBs were made from material obtained by single pass. Cellularity of smears and corresponding cell blocks were assessed and categorized according to a scoring system (score 1 to 3 for number of cells <50, 50-100, >100, respectively). Preserved architecture and morphology were also assessed in smears and CBs.

Results

The evaluated samples showed a cellularity score 3 in 65.4%CBs and score 2 in 24.7% CBs. Overall, 90.1% cell blocks had acceptable cellularity. Cell morphology was preserved in all CBs of acceptable cellularity, except for two adenocarcinoma, one squamous cell carcinoma, and one small cell carcinoma blocks. Cellular architecture was also preserved in all CBs of acceptable cellularity.

Conclusions

This simple improvised technique of CB preparation optimized its cellularity, morphology, and architectural preservation, even after adequate cellular FNA smears.

Application of Immunocytochemistry on Cell Block Sections for the Investigation of Thyroid Lesions

OBJECTIVE

To investigate the potential of Classification and Regression Trees (CARTs) for the diagnosis of thyroid lesions based on cell block immunocytochemistry and cytological outcome.

STUDY DESIGN

A total of 956 histologically confirmed cases (673 benign and 283 malignant) from patients with thyroid nodules were prepared via liquid-based cytology and evaluated; 4 additional slides were stained for cytokeratin 19 (CK-19), galectin 3 (Gal-3), Hector Battifora mesothelial cell 1 (HBME-1), and thyroglobulin. On the basis of immunocytochemistry and the cytological diagnosis, a CART algorithm was constructed and used for evaluation.

RESULTS

The major important factors contributing to the diagnostic CART model were: cytological outcome, CK-19, Gal-3, and HBME-1. The sensitivity and specificity of the cytological diagnosis were 96.27% and 88.26%, respectively (cut-off: category 3 of The Bethesda System [TBS-3]). The introduction of immunocytochemistry and the CART model increased the sensitivity and specificity to 98.88% and 99.11%, respectively. CK-19 presented the best performance for discriminating papillary thyroid carcinomas, followed by HBME-1 and Gal-3. In the TBS-2 cases, CK-19 and, subsequently, Gal-3 were important immunocytochemistry markers. Ultimately, CK-19 and HBME-1 on TBS-5 or TBS-6 cases demonstrated the best results.

CONCLUSIONS

The hierarchical structure of the CART model provides a diagnostic algorithm linked with the risk of malignancy at every step of the procedure. It also provides guidance on the use of ancillary examinations as it goes by simple, human understandable rules.

The utility of cellient cell blocks in low-cellularity thyroid fine needle aspiration biopsies

BACKGROUND

Low cellularity can be problematic in thyroid fine needle aspiration (FNA) biopsies. The Cellient cell block (CB) system has been reported to improve cell recovery compared to traditional methods. Therefore, we studied the utility of Cellient CBs in the evaluation of thyroid FNAs, with an emphasis on low-cellularity specimens.

METHODS

ThinPrep slides were prepared from thyroid FNAs submitted in Cytolyt. After assessment using TBSRTC criteria, Cellient CBs were requested on samples with residual FNA material and an initial cytologic impression of non-diagnostic, AUS/FLUS, and on apparently benign samples with marginally adequate cellularity. The contribution of the CB findings to the final diagnosis was assessed.

RESULTS

965 cases of paired ThinPrep and CB sections were examined. Overall, the cell block findings resulted in a change of the initial ThinPrep impression in 15% (n = 148) of cases. The vast majority of these changed cases were initially inadequate for interpretation, and specifically, 31% (n = 123) of the non-diagnostic ThinPrep samples became diagnostic with a CB. The cell block findings contributed to a change in diagnosis in 8% (n = 23) of AUS/FLUS cases, and in less than 1% of low-cellularity benign samples.

CONCLUSION

The use of CBs in low-cellularity thyroid FNAs has not been well described. In this study, we found that the contribution of CBs in this setting varied by TBSRTC category. Specifically, the samples that benefited most were initially non-diagnostic specimens and select cases of AUS/FLUS, while low-cellularity benign samples gained very little additional information. Diagn. Cytopathol. 2016;44:737-741. © 2016 Wiley Periodicals, Inc.

Cell-block procedure in endoscopic ultrasound-guided-fine-needle-aspiration of gastrointestinal solid neoplastic lesions

In the present review we have analyzed the clinical applications of endoscopic ultrasound-guided-fine-needle-aspiration (EUS-FNA) and the methodological aspects obtained by cell-block procedure (CBP) in the diagnostic approach to the gastrointestinal neoplastic pathology. CBP showed numerous advantages in comparison to the cytologic routine smears; in particular, better preservation of cell architecture, achievement of routine haematoxylin-eosin staining equivalent to histological slides and possibility to perform immunohistochemistry or molecular analyses represented the most evident reasons to choose this method. Moreover, by this approach, the differential diagnosis of solid gastrointestinal neoplasias may be more easily achieved and the background of contaminant non-neoplastic gastrointestinal avoided. Finally, biological samples collected by EUS-FNA CBP-assisted should be investigated in order to identify and quantify further potential molecular markers.

Comparison of the Cellient(™) automated cell block system and agar cell block method

OBJECTIVE

To compare the Cellient(TM) automated cell block system with the agar cell block method in terms of quantity and quality of diagnostic material and morphological, histochemical and immunocytochemical features.

MATERIALS AND METHODS

Cell blocks were prepared from 100 effusion samples using the agar method and Cellient system, and routinely sectioned and stained for haematoxylin and eosin and periodic acid-Schiff with diastase (PASD). A preliminary immunocytochemical study was performed on selected cases (27/100 cases). Sections were evaluated using a three-point grading system to compare a set of morphological parameters. Statistical analysis was performed using Fisher's exact test.

RESULTS

Parameters assessing cellularity, presence of single cells and definition of nuclear membrane, nucleoli, chromatin and cytoplasm showed a statistically significant improvement on Cellient cell blocks compared with agar cell blocks (P < 0.05). No significant difference was seen for definition of cell groups, PASD staining or the intensity or clarity of immunocytochemical staining. A discrepant immunocytochemistry (ICC) result was seen in 21% (13/63) of immunostains.

CONCLUSION

The Cellient technique is comparable with the agar method, with statistically significant results achieved for important morphological features. It demonstrates potential as an alternative cell block preparation method which is relevant for the rapid processing of fine needle aspiration samples, malignant effusions and low-cellularity specimens, where optimal cell morphology and architecture are essential. Further investigation is required to optimize immunocytochemical staining using the Cellient method.

Cell blocks in cytopathology: a review of preparative methods, utility in diagnosis and role in ancillary studies

The cell block (CB) is a routine procedure in cytopathology that has gained importance because of its pivotal role in diagnosis and ancillary studies. There is no precise review in the published literature that deals with the various methods of preparation of CB, its utility in diagnosis, immunocytochemistry (ICC) or molecular testing, and its drawbacks. An extensive literature search on CB in cytology using internet search engines was performed for this review employing the following keywords: cell block, cytoblock, cytology, cytopathology, methods, preparation, fixatives, diagnostic yield, ancillary and molecular studies. Ever since its introduction more than a century ago, the CB technique has undergone numerous modifications to improve the quality of the procedure; however, the overall principle remains the same in each method. CBs can be prepared from virtually all varieties of cytological samples. In today's era of personalized medicine, cytological specimens, including CBs, augment the utility of cytological samples in analysing the molecular alterations as effectively as surgical biopsies or resection specimens. With the availability of molecular targeted therapy for many cancers, a large number of recent studies have used cytological material or CBs for molecular characterization. The various techniques of CB preparation with different fixatives, their advantages and limitations, and issues of diagnostic yield are discussed in this review.

Automated Cellient(™) cytoblocks: better, stronger, faster?

OBJECTIVE

Cytoblocks (CBs), or cell blocks, provide additional morphological detail and a platform for immunocytochemistry (ICC) in cytopathology. The Cellient(™) system produces CBs in 45 minutes using methanol fixation, compared with traditional CBs, which require overnight formalin fixation. This study compares Cellient and traditional CB methods in terms of cellularity, morphology and immunoreactivity, evaluates the potential to add formalin fixation to the Cellient method for ICC studies and determines the optimal sectioning depth for maximal cellularity in Cellient CBs.

METHODS

One hundred and sixty CBs were prepared from 40 cytology samples (32 malignant, eight benign) using four processing methods: (A) traditional; (B) Cellient (methanol fixation); (C) Cellient using additional formalin fixation for 30 minutes; (D) Cellient using additional formalin fixation for 60 minutes. Haematoxylin and eosin-stained sections were assessed for cellularity and morphology. ICC was assessed on 14 cases with a panel of antibodies. Three additional Cellient samples were serially sectioned to determine the optimal sectioning depth. Scoring was performed by two independent, blinded reviewers.

RESULTS

For malignant cases, morphology was superior with Cellient relative to traditional CBs (P < 0.001). Cellularity was comparable across all methods. ICC was excellent in all groups and the addition of formalin at any stage during the Cellient process did not influence the staining quality. Serial sectioning through Cellient CBs showed optimum cellularity at 30-40 μm with at least 27 sections obtainable.

CONCLUSIONS

Cellient CBs provide superior morphology to traditional CBs and, if required, formalin fixation may be added to the Cellient process for ICC. Optimal Cellient CB cellularity is achieved at 30-40 μm, which will impact on the handling of cases in daily practice.

Five Top Stories in Cytopathology

Context.—Cytology relies heavily on morphology to make diagnoses, and morphologic criteria have not changed much in recent years. The field is being shaped predominantly by new techniques for imaging and for acquiring and processing samples, advances in molecular diagnosis and therapeutics, and regulatory issues.

Objective.—To review the importance of classical morphology in the future of cytopathology, to identify areas in which cytology is expanding or contracting in its scope, and to identify factors that are shaping the field.

Data Sources.—Literature review.

Conclusions.—Five stories paint a picture in which classical cytomorphology will continue to have essential importance, both for diagnosis and for improving our understanding of cancer biology. New endoscopy and imaging techniques are replacing surgical biopsies with cytology samples. New molecularly targeted therapies offer a chance for cytology to play a major role, but they pose new challenges. New molecular tests have the potential to synergize with, but not replace, morphologic interpretation of thyroid fine-needle aspirations. Ultrasound-guided fine-needle aspiration performed by cytopathologists is opening a new field of “interventional cytopathology” with unique value. For the productive evolution of the field, it will be important for cytopathologists to play an active role in clinical trials that document the ability of cytology to achieve cost-effective health care outcomes.

The influence of rapid onsite evaluation on the adequacy rate of fine-needle aspiration cytology: a systematic review and meta-analysis

Rapid onsite evaluation (ROSE) has the potential to improve the adequacy rates of fine-needle aspiration (FNA) cytology. Studies have obtained variable results on the influence of ROSE. We conducted a systematic review and meta-analysis of studies on the influence of ROSE on FNA adequacy. We synthesized evidence across all anatomic locations. We only included studies that contained a control arm and compared cohorts with ROSE against cohorts without ROSE at a single location. We screened 2,179 studies and identified 25 studies that met our inclusion criteria. On average, ROSE improves the adequacy rate by 12%, but there was considerable variability across studies. The adequacy rate with ROSE depends on the non-ROSE adequacy rate. Sixty-five percent of the variability in the adequacy rate with ROSE was found to occur because of differences in the adequacy rate without ROSE. Studies with high non-ROSE adequacy rates showed low improvement after ROSE was implemented. Studies must account for the effect of the non-ROSE adequacy rate to determine the effect of ROSE on FNA adequacy rates.

Effectiveness of the cell block technique in diagnostic cytopathology

Background:

One of the constraints of the conventional FNA smear is the limited material available for adjuvant diagnostic investigations including immunocytochemistry. The cell block technique employs the retrieval of small tissue fragments from a FNA specimen which are processed to form a paraffin block. It is widely accepted that cell block technique increases the cellular yield and improves diagnostic accuracy. The ability to obtain numerous tissue sections allows for multiple immunostains and other studies to be performed akin to paraffin sections produced in histopathology.

Aims:

To determine the effectiveness of the cell block technique by comparing cytomorphological preservation and immunocytochemistry (ICC) stains on paired cell block and conventional fine needle aspiration (FNA) samples.

Materials and Methods:

In this prospective study, material for both glass slides and cell blocks were collected simultaneously during fine needle aspirates from 47 samples comprising lung and liver masses. Grading of cellularity, morphological preservation, architectural preservation, immunocytochemical staining intensity and presence of background staining on paired FNA smears and cell block samples were compared. Each arm of the paired analysis was performed blindly without knowledge of the grading outcome of the other. The Kappa statistic (κ) was used to measure inter-rater agreement.

Results:

The 47 samples evaluated included FNAs from the lung, 24/47 (51%) and liver, 23/47 (49%). The immunocytochemistry stains consisted of 44/47 (94%) CK7; 44/47 (94%) CK20; 18/47 (38%) TTF1; 10/47 (21%) synaptophysin; 10/47 (21%) Hepar-1 and 7/47 (15%) AE1/3. There was no overall agreement in preservation of cytomorphological detail and ICC staining between the two methods. The Papanicolaou-stained conventional FNA smears fared better than the cell block for the evaluation of nuclear and morphologic characteristics. The ICC stains worked better on the cell block samples due to lack of background and aberrant staining.

Conclusion:

Direct FNA smears and cell blocks complement each other and our results indicate that both are needed in the diagnostic work-up of patients. The cost implications of performing both techniques on all FNA material warrants further evaluation.

A cell-block preparation using glucomannan extracted from Amorphophallus konjac

To evaluate a cell-block preparation using glucomannan, which was extracted from Amorphophallus konjac. Ten specimens were centrifuged at 1,500 rpm for 5 minutes, the supernatant was removed; the remnant after the preparation of smear specimens for routine cytological examination was fixed with 20% formalin. The specimen was recentrifuged at 1,500 rpm for 5 minutes, and the supernatant was removed. The residue was resuspended with 2 ml of eosin solution and 1-5 ml of 80% alcohol, and stirred well. After further centrifugation, the supernatant was removed, and one drop of a glucomannan-formalin water solution was added gently. After immersion in methanol for 2 hours, glucomannan is solidified and becomes gelatinous. The obtained cell block was placed in the cassette for the preparation of tissue specimens, dehydrated by the routine method, infiltrated with paraffin, and a paraffin-embedded block was prepared. Thin sections were prepared from the paraffin-embedded cell block, and hematoxylin-eosin (H&E) stain with immunological stains was performed. H&E stain, periodic acid-Schiff reaction, Alcian blue, and immunohistochemical stain were clearly demonstrated.We evaluated a new modality of cell-block preparation using a glucomannan-formalin water solution. We found that the method was easy to perform and thought it could be useful as an alternative technique for cell-block preparations. Thus, this novel technique should find wide application in the future.

Cellient™ automated cell block versus traditional cell block preparation: a comparison of morphologic features and immunohistochemical staining

Traditional cell block (TCB) sections serve as an important diagnostic adjunct to cytologic smears but are also used today as a reliable preparation for immunohistochemical (IHC) studies. There are many ways to prepare a cell block and the methods continue to be revised. In this study, we compare the TCB with the Cellient™ automated cell block system. Thirty-five cell blocks were obtained from 16 benign and 19 malignant nongynecologic cytology specimens at a large university teaching hospital and prepared according to TCB and Cellient protocols. Cell block sections from both methods were compared for possible differences in various morphologic features and immunohistochemical staining patterns. In the 16 benign cases, no significant morphologic differences were found between the TCB and Cellient cell block sections. For the 19 malignant cases, some noticeable differences in the nuclear chromatin and cellularity were identified, although statistical significance was not attained. Immunohistochemical or special stains were performed on 89% of the malignant cases (17/19). Inadequate cellularity precluded full evaluation in 23% of Cellient cell block IHC preparations (4/17). Of the malignant cases with adequate cellularity (13/17), the immunohistochemical staining patterns from the different methods were identical in 53% of cases. The traditional and Cellient cell block sections showed similar morphologic and immunohistochemical staining patterns. The only significant difference between the two methods concerned the lower overall cell block cellularity identified during immunohistochemical staining in the Cellient cell block sections.