Rapid on-site evaluation and cell blocks: getting the most from the least invasive method in cytopathology

INTRODUCTION

Fine needle aspiration cytology (FNAC) sampling is a minimally invasive procedure done to identify the pathology behind superficial and deep-seated lesions. Rapid on-site evaluation (ROSE) can be an adjunct to the FNACs. Our study aimed to identify the role of ROSE in diagnostic adequacy and to check the benefit of cell block (CB)/cell buttons prepared from the ROSE samples.

MATERIAL AND METHODS

A prospective study was conducted where all patients referred for FNAC were included. ROSE using 1% aqueous toluidine blue stain and CB/cell button preparations were done for the identification of various cytological lesions.

RESULTS

Among 600 cases included in the study most common age group was third and fourth decades with a mean age of 41.6 years and M: F ratio of 1:1.7. Ultrasound-guided procedures were done in 20% of cases. CB preparation was available in 14% of cases. Most CBs were from the cases wherein ROSE was performed 81% (77 out of 86), with CB helping in making an accurate diagnosis in 17% of cases. Lymph nodes 26%, and thyroid 23% were the most common sites for sampling with the highest number of repeat procedures from non-ROSE cases (14%). The non-diagnostic rate for non-ROSE cases was 7.7% (23/300) even after the repeat procedures as compared to 1.3% (4/300) for ROSE. Three slides on average were consumed in ROSE-performed procedures, as compared to an average of 5 slides in non-ROSE. The average turnaround time was 1.7 days for non-ROSE cases and 1.05 for ROSE cases respectively. Cyto-histopathological correlation was available in 40% of cases with a sensitivity of 98.1%, specificity of 96.7%, positive predictive value of 90%, negative predictive value of 99.4%, and diagnostic accuracy of 97%. The correlation of CB, number of slides consumed, and turnaround time among the 2 groups were statistically significant (P value < 0.001).

CONCLUSIONS

ROSE is a method used to assess material aspirated at the time of FNAC procedures to determine the adequacy and to an extent to identify whether the lesion is neoplastic or non-neoplastic. CBs have helped in increasing diagnostic accuracy apart from the fact that the paraffin-embedded tissue material can be used for further studies.

Heat Induced Processing of Cellblocks with Significant Reduction in Overall Turn Around Time

Introduction

Cellblock (CB) with immunohistochemistry (IHC) is practically indispensable in the diagnostic workup of serous effusions; however, CB requires a minimum of 15-20 h for routine histopathological processing. A reduction in processing time can expedite a faster diagnosis.

Aim

This study was undertaken to evaluate the utility of the heat-induced CB (HICB) technique.

Material and Methods

Two sets of agar-embedded CBs were processed from 50 effusion samples. CBs were further processed by conventional and rapid methods. Conventional CBs (CCB) were processed in a histoprocessor, whereas rapid CB was processed in a heated water bath with an agitation facility. For HICB processing, dehydration and clearing were performed at 50°C followed by paraffin wax impregnation at 65°C temperature. From both CBs, sections of 5 um thickness were cut and stained with hematoxylin and eosin (H and E). Cell morphology, cost, and time were compared between the two methods. The feasibility of IHC was attempted in a few cases.

Results

HICB was completed within 4.30 h compared with CCB. Diagnoses on both CBs were concordant in all the cases. Incomplete dehydration was noted in six (12%) cases, but the diagnosis was not compromised. No additional cost was involved in HICB. On IHC, both HICB and CCB exhibited equivalent expression.

Conclusions

HICB is a rapid, innovative, simple, and cost-effective technique and expedites faster diagnosis. It does not require any advanced equipment.

Lifting the lid over the pearl: A histological insight

Epithelial pearls and Keratin pearls are pathognomonic of squamous cell carcinoma. However, their histogenesis is not well understood. Only a handful of studies have been conducted in the past in this regard. This brief communication aims to understand the formation of these pearls with a few of our own experiences.

ROSE in Rosai-Dorfman-Destombes (RDD) disease: a cytological diagnosis

Background

Rosai–Dorfman–Destombes (RDD) is also known as sinus histiocytosis with massive lymphadenopathy (SHML). It is a benign proliferative disorder of histiocytes, affecting lymph nodes, rarely with extra-nodal involvement. Rapid on-site evaluation (ROSE) with fine-needle aspiration cytology (FNAC) can be utilized as a minimally invasive investigation to avoid unnecessary surgery of this self-limiting disease.

Case presentation

A 65-year-old female presented with complaints of bilateral cervical lymphadenopathy since 1 year. Rapid on-site stain with FNAC from bilateral cervical lymph nodes revealed features of Rosai–Dorfman–Destombes (RDD) disease.

Conclusion

FNAC with rapid on-site evaluation can provide a simple and cost-effective method for looking at the unique cytological features of the disease and act as a first-line investigation.

Cell-blocks and immunohistochemistry

The interpretation of results on immunostained cell-block sections has to be compared with the cumulative published data derived predominantly from formalin-fixed paraffin-embedded (FFPE) tissue sections. Because of this, it is important to recognize that the fixation and processing protocol should not be different from the routinely processed FFPE surgical pathology tissue. Exposure to non-formalin fixatives or reagents may interfere with the diagnostic immunoreactivity pattern. The immunoprofile observed on such cell-blocks, which are not processed in a manner similar to the surgical pathology specimens, may not be representative resulting in aberrant results. The field of immunohistochemistry (IHC) is advancing continuously with the standardization of many immunomarkers. A variety of technical advances such as multiplex IHC with refined methodologies and automation is increasing its role in clinical applications. The recent addition of rabbit monoclonal antibodies has further improved sensitivity. As compared to the mouse monoclonal antibodies, the rabbit monoclonal antibodies have 10 to 100 fold higher antigen affinity. Most of the scenarios involve the evaluation of coordinate immunostaining patterns in cell-blocks with relatively scant diagnostic material without proper orientation which is usually retained in most of the surgical pathology specimens. These challenges are addressed if cell-blocks are prepared with some dedicated methodologies such as NextGen CelBloking™ (NGCB) kits. Cell-blocks prepared by NGCB kits also facilitate the easy application of the SCIP (subtractive coordinate immunoreactivity pattern) approach for proper evaluation of coordinate immunoreactivity. Various cell-block and IHC-related issues are discussed in detail.

The Value of Cellblock in Diagnosing Pancreatic Lymphomas

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the diagnostic tool of choice for pancreatic solid mass lesions. Pancreatic lymphomas represent an infrequent and challenging cytologic diagnosis. Our aim was to determine the diagnostic value of cellblock (CB) in the diagnosis of pancreatic lymphomas.

METHODS

We retrieved pancreatic EUS-FNAs performed over 10-years from our institution's database. We correlated the cytologic and CB diagnosis with the histologic diagnosis as a gold standard.

RESULTS

We found 5 cases (2 women and 3 men; age range, 37-66 years [average age, 52 years]) of pancreatic lymphomas with histologic follow-up biopsies. They included 1 case of T-cell lymphoma (TCL), 1 case of plasma cell neoplasm (multiple myeloma [MM]), 1 case of diffuse large B-cell lymphoma (DLBCL), 1 case of classic Hodgkin lymphoma (HL), and 1 case of high-grade B-cell lymphoma (HGBCL). Cytologically, the cases of HL and DLBCL were suspected, the cases of TCL and MM were confused with undifferentiated carcinoma and neuroendocrine carcinoma, and the case of HGBCL was inconclusive. CB samples were of value in highlighting the morphologic details of lymphomas and allowed confirmation, proper classification, and grading of the lymphomas using immunohistochemistry that matched tissue biopsies.

CONCLUSIONS

EUS-FNA smears with CBs are helpful diagnostic tools, differentiating lymphomas from other malignancies and from nonneoplastic lymphocyte-rich lesions. CBs allow proper classification and grading of cases of pancreatic lymphomas.

Comparison of FNAC smears, cytospin smears, and cellblocks of transthoracic guided FNAC of suspected lung tumor: A study of 100 cases

Introduction:

Transthoracic guided fine needle aspiration cytology (FNAC) of clinically suspected lung tumors is an increasingly common procedure in diagnosis. Cytospin Smear and Cellblock preparations of available material are helpful in subtyping and confirming the diagnosis, and they can also be used for further studies, i.e., special stain and immunohistochemistry, etc.

Aims and Objectives:

This research was undertaken to study the technique of guided transthoracic lung FNAC of clinically suspected lung tumors and the establish role of FNAC smears, cytospin smears, and cellblocks in the detection and typing of neoplastic lung lesions and correlation.

Materials and Methods:

Guided FNAC was taken from 100 cases of clinically suspected lung tumor and FNAC smears, cytospin smears, and cellblocks of aspirated material were studied over a period of 2 years from September 2011 to September 2013.

Results:

The material adequacies were 80% in FNAC smears, 83% in cytospin smears, and 89% in cellblocks. Additional information supported by cytospin smear and cellblock was 3% and 9%, respectively. Architectural preservation was better in FNAC smears (85%) and cellblocks (73.03%) than that in cytospin smears (31.33%). Morphological preservation was better in FNAC smears (90%) and cellblocks (75.28%) than that in cytospin smears (14.46%). Diagnostic accuracy was increased in the cellblocks and cytospin smears.

Conclusion:

Cytospin smear was helpful when low cellular material was obtained, and the concomitant examination of cellblocks not only confirmed the diagnosis of malignancy but also helped in classifying the obtained material and allowed further study on the same.