Molecular techniques in cytopathology practice

Molecular/biomarker testing in lung cytology: A practical approach

The increasing comprehension of molecular mechanisms underlying lung cancer and the discovery of targetable genomic alterations has dramatically change the pathological approach to lung cancer, especially non-small cell lung cancer (NSCLC). This unstoppable knowledge has taken pathologists to the leading front on lung cancer management. This is especially relevant in the world of cytopathology where "doing more with less" is a daily challenge. Nowadays with a growing number of predictive biomarkers needed to manage patients with NSCLC, there has been a paradigm shift in care and handling of diagnostic samples. One of the main emphasis and interest relies on the utilization of cytologic samples and small biopsies for not only diagnostic purposes but also for ancillary testing. Moreover, lung cytopathology is in continuous evolutions with implementation of new diagnostic techniques, new tools, and facing new challenges. The goal of this paper will be to provide the reader with the necessary concepts than can be used to exploit the cytological samples in order to use these samples for comprehensive diagnosis and relevant ancillary testing purposes.

Pediatric Small Round Blue Cell Tumors: Cytopathological Puzzle or an Intriguing Scientific Window?

BACKGROUND

Small round blue cell tumors or more commonly called small round cell tumors (SRCTs) are undifferentiated neoplasms, sharing an overlapping morphological pattern of small round blue cells. Diagnosing these tumors represents a complex challenge for cytopathologists and for general surgical pathologist alike. This stems from the fact that these tumors share not only similar morphological features, but also some immunophenotypic characteristics, thus requiring a broad panel of antibodies, which might not be included in the most basic immunohistochemistry panels, used in the routine work of most pathology laboratories. Furthermore, one should note that the diagnosis, prognosis, and/or therapeutic decision are often dependent on the knowledge of the existence of specific molecular alterations, which requires access to sophisticated molecular ancillary techniques. Cytological diagnosis of SRCT should be systematized. A thorough understanding of the morphological pattern of these tumors, the small details they entail, the background and cellular patterns, and the nuclear and cytoplasmic peculiarities, may hint to the most probable diagnosis. Minor clues, such as the presence of a fibrillar background, the presence of rosettes or a specific "salt and pepper" chromatin, are important clues toward a probable diagnosis of a neuroblastoma, or the presence of a tigroid background is a characteristic of rhabdomyosarcoma and the Ewing family tumors. However, in poorly differentiated tumors, morphology alone will not suffice, making it essential for the access to complementary diagnostic techniques in order to reach the final diagnosis. Summary and Key Messages: The cytological diagnosis and treatment of SRCTs require an experienced, well-articulated, proficient teamwork, and sophisticated complementary diagnostic techniques, only available in centers of reference.

Cervical Cytology of Samples with Ureaplasma urealyticum, Ureaplasma parvum, Chlamydia trachomatis, Trichomonas vaginalis, Mycoplasma hominis, and Neisseria gonorrhoeae Detected by Multiplex PCR

Introduction

Despite increasing application of molecular diagnostic methods for the detection of sexually transmitted infections, the cytological findings in pap smears of patients with pathogens that can be identified only by PCR are not yet well described. The aim of this study was to describe the most common cytological features in cervical pap smears of patients with Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis, Mycoplasma hominis, Ureaplasma urealyticum, and Ureaplasma parvum detected by multiplex PCR.

Methods

Cervical samples for conventional and liquid-based cytology and for multiplex PCR were collected from women ranging from 23 to 54 years old, who underwent routine screening at a gynecological Unit.

Results

Multiplex PCR was positive in 36.2% of the samples: Ureaplasma parvum 14.9%, Chlamydia trachomatis 10.6%, Trichomonas vaginalis 10.6%, Mycoplasma hominis 8.5%, Ureaplasma urealyticum 4.2%, Neisseria gonorrhoeae 2.1%, and Mycoplasma genitalium (0). Multiple pathogens were observed in 12.8% of samples. Microscopic cervicitis (≥10 polymorphonuclear leukocytes/epithelial cell) and normal (predominantly lactobacillary) microbiota were the most frequent findings in the samples in which the pathogens were detected alone or in multiple infections, except for samples with Trichomonas vaginalis in which the coccobacillary microbiota was the most common. In samples with microscopic cervicitis and normal microbiota, those with at least one pathogen identified by multiplex PCR were significantly more frequent than those with no pathogen, 66.6% versus 33.3%.

Conclusion

Failure to identify an inflammatory agent in pap smear with intense neutrophil exudate may suggest the presence of Ureaplasma parvum, Ureaplasma urealyticum, Chlamydia trachomatis, or Trichomonas vaginalis. A remark on the intensity of inflammation should be made in the reports of cervical pap smears so that this cytological finding can be correlated with clinical and PCR results.

BRAF and TERT promoter mutations: clinical application in thyroid cancer

Given the long-term survival of most patients with thyroid cancer, it is very important to distinguish patients who need aggressive treatment from those who do not. Conventional clinicopathological prognostic parameters could not completely predict the final outcome of each patient. Recently, molecular marker-based risk stratification of thyroid cancer has been proposed to better estimate the cancer risk. Although BRAF mutation has drawn much attention based on its high prevalence, its association with recurrence or mortality is not clear. Recently, telomerase reverse transcriptase (TERT) promoter mutation has been identified in thyroid cancer. It increases telomerase activity, which allows cancer cells to immortalize. It was found in 10 to 20% of differentiated thyroid carcinoma and 40% of dedifferentiated thyroid carcinoma. It is highly prevalent in old age, large tumor, aggressive histology, advanced stages, and distant metastasis. It is associated with increased recurrence and mortality. Concomitant BRAF and TERT promoter mutations worsen the survival rate. Inclusion of TERT promoter mutation analysis with conventional clinicopathological evaluation can lead to better prognostication and management for individual patients.

Management of cytological material, pre-analytical procedures and bio-banking in effusion cytopathology

Serous effusion fluid is one of the most commonly encountered specimens in routine cytopathology practice. It provides invaluable information about the patient and the clinical status; but to get the most of it, specimen handling and processing must be carried out properly. Cytomorphology is the basis of a successful analysis which should complemented by ancillary tests when needed. A wide spectrum of ancillary techniques - ranging from immunocytochemistry and flow cytometry to different assays of molecular pathology - can be applied to serous effusions. This article describes the acquisition and management of serous effusion fluids, methods for preservation and transportation, different techniques of cytopreparation, application of immunocytochemistry, flow cytometry, and fluorescence in-situ hybridization (FISH), as well as DNA extraction for polymerase chain reaction (PCR) and next generation sequencing (NGS). Principles of bio-banking of effusion samples are also discussed which is getting more important in correlation with the developments in personalized medicine.

Comparison between cytospin and liquid-based cytology in cerebrospinal fluid diagnosis of neoplastic diseases: A single institution experience

OBJECTIVE

The current tools available for detecting malignant neoplasms in the cerebrospinal fluid (CSF) are neurological examination, followed by neuroimaging, cytology and molecular techniques. To highlight the role of cytology the diagnosis of metastatic tumours in CSF samples, we present our experience using cytospin and ThinPrep liquid-based cytology.

METHODS

A retrospective analysis was conducted using the pathological records of 8181 cytological specimens of CSF, which were diagnosed over a 17-year period. Between 2000 and 2014, a total of 6994 CSF samples were processed using cytospin method and 1187 specimens were examined using ThinPrep method in the period between 2015 and 2017.

RESULTS

The most frequent metastatic neoplasm of the first period was non-Hodgkin lymphoma; in the second period the commonest malignancy found was brain tumour (glioblastoma and medulloblastoma). The samples processed by cytospin revealed cytolysis and haemorrhage, while the cases processed by ThinPrep had a clear background. Ten false-positive cases belonging to the suspicious category were processed by cytospin, while there was only one false positive case in the group processed by ThinPrep. The positive predictive value was 95% in cytospin and 100% in Thin Prep with comparable sensitivity, specificity, diagnostic accuracy and negative predictive values.

CONCLUSIONS

CSF cytology is a reliable technique for identifying malignancy in CSF. ThinPrep technology can be applied with good results in terms of clear background, cell enrichment, better nuclear details and high cellularity per slide.

Cervical cancer screening by molecular Pap-transformation of gynecologic cytology

BACKGROUND

Cervical cancer is one of the common cancers in women accounting for 7.9% of all cancers. In India it is the second commonest cancer in women. The immortality of the cancer cell and the relatively long time frame from acquisition of infection to development of cervical cancer was established. As major advancements like LBC, HPV testing were introduced in the recent years, screening has taken a new avatar, the Molecular pap!! The objectives of this study were: To compare gynecologic cytology and abnormal results with respect to conventional and LBC. To study the role of HPV cotesting and ancillary tests performed, that is, HPV CISH, and p16ink4a by IHC.

METHODS

About 71 924 Conventional and LBC samples were included from August 2009 to December 2017. Cases for HPV testing along the conventional smears were 1539. HPV can be tested from the same LBC vial as the sample remains stable at room temperature for 6 weeks. HPV DNA PCR was carried out in our laboratory for High and Low risk genotypes. Cytology findings were also correlated with histology.

RESULTS

Detection rate of SILs in LBC samples were higher (2.20%). The commonest abnormality was LSIL in LBC and ASCUS in conventional smears. Commonest HR HPV and LR HPV detected was 1 61 856 and 61 142.

CONCLUSION

LBC with HPV cotesting improves sensitivity and specificity and reduces ambiguous results; allows better compliance, as a negative result of both tests allows patients to get screening every 5 years, thereby increasing screening intervals, important in a resource limited situation.

Lung cancer samples preserved in liquid medium: One step beyond cytology

Lung cancer is one of the most common cancer types in men and women worldwide with a high mortality rate. World Health Organization (WHO) classification has accepted biopsy as the primary sample for lung cancer diagnosis, pathological classification and molecular testing for management of patients, yet, the use of alternative sampling procedures is highly encouraged. Bronchial cytological samples require a less invasive collection technique and may be suitable for pathological and molecular analysis and storage in liquid medium. Furthermore, the molecular analysis of bronchial cytological samples allows the detection of molecular biomarkers, which may be useful for the selection of molecular targeted therapies. Thus, the purpose of this review is to describe the usefulness of bronchial cytological samples preserved in liquid medium from lung cancer patients for pathological diagnosis and molecular investigation.

The Role of Liquid Based Cytology and Ancillary Techniques in the Peritoneal Washing Analysis: Our Institutional Experience

Background

The cytological analysis of peritoneal effusions serves as a diagnostic and prognostic aid for either primary or metastatic diseases. Among the different cytological preparations, liquid based cytology (LBC) represents a feasible and reliable method ensuring also the application of ancillary techniques (i.e immunocytochemistry-ICC and molecular testing).

Methods

We recorded 10348 LBC peritoneal effusions between January 2000 and December 2014. They were classified as non-diagnostic (ND), negative for malignancy-NM, atypical-suspicious for malignancy-SM and positive for malignancy-PM.

Results

The cytological diagnosis included 218 ND, 9.035 NM, 213 SM and 882 PM. A total of 8048 (7228 NM, 115SM, 705 PM) cases with histological follow-up were included. Our NM included 21 malignant and 7207 benign histological diagnoses. Our 820 SMs+PMs were diagnosed as 107 unknown malignancies (30SM and 77PM), 691 metastatic lesions (81SM and 610PM), 9 lymphomas (2SM and 7PM), 9 mesotheliomas (1SM and 8SM), 4 sarcomas (1SM and 3PM). Primary gynecological cancers contributed with 64% of the cases. We documented 97.4% sensitivity, 99.9% specificity, 98% diagnostic accuracy, 99.7% negative predictive value (NPV) and 99.7% positive predictive value (PPV). Furthermore, the morphological diagnoses were supported by either 173 conclusive ICC results or 50 molecular analyses. Specifically the molecular testing was performed for the EGFR and KRAS mutational analysis based on the previous or contemporary diagnoses of Non Small Cell Lung Cancer (NSCLC) and colon carcinomas. We identified 10 EGFR in NSCCL and 7 KRAS mutations on LBC stored material.

Conclusions

Peritoneal cytology is an adjunctive tool in the surgical management of tumors mostly gynecological cancers. LBC maximizes the application of ancillary techniques such as ICC and molecular analysis with feasible diagnostic and predictive yields also in controversial cases.

Cytopathology of Follicular Cell Nodules

The detection of thyroid nodules, consisting of different diseases, represents a common finding in population. Their evaluation and diagnosis are mostly achieved with fine-needle aspiration cytology (FNAC). Even though the majority of thyroid nodules are correctly diagnosed, a total of 25% to 30% of them are classified "indeterminate" comprising lesions with varying risk of malignancy and different types of management. Although the number of thyroid FNACs, including small lesions, is increasing due to the reliance upon sonographic and cytologic interpretations, there are issues concerning cytomorphologic interpretation and interobserver reproducibility. Different classification systems have tried to better define the criteria for inclusion in specific categories and to therefore reduce the rate of indeterminate diagnoses such as atypia of undetermined significance, follicular neoplasms, and suspicious for malignancy. However, the support of ancillary techniques (eg, immunocytochemistry and molecular analysis) are reshaping morphologic diagnoses made on materials obtained from FNAC.

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.

Critical Analyses of the Introduction of Liquid-Based Cytology in a Public Health Service of the State of São Paulo, Brazil

OBJECTIVE

The aim of this study was to compare the performance of the current conventional Pap smear with liquid-based cytology (LBC) preparations.

STUDY DESIGN

Women routinely undergoing their cytopathological and histopathological examinations at Fundação Oncocentro de São Paulo (FOSP) were recruited for LBC. Conventional smears were analyzed from women from other areas of the State of São Paulo with similar sociodemographic characteristics.

RESULTS

A total of 218,594 cases were analyzed, consisting of 206,999 conventional smears and 11,595 LBC. Among the conventional smears, 3.0% were of unsatisfactory preparation; conversely, unsatisfactory LBC preparations accounted for 0.3%. The ASC-H (atypical squamous cells - cannot exclude high-grade squamous intraepithelial lesion) frequency did not demonstrate any differences between the two methods. In contrast, the incidence of ASC-US (atypical squamous cells of undetermined significance) was almost twice as frequent between LBC and conventional smears, at 2.9 versus 1.6%, respectively. An equal percentage of high-grade squamous intraepithelial lesions were observed for the two methods, but not for low-grade squamous intraepithelial lesions, which were more significantly observed in LBC preparations than in conventional smears (2.2 vs. 0.7%). The index of positivity was importantly enhanced from 3.0% (conventional smears) to 5.7% (LBC).

CONCLUSIONS

LBC performed better than conventional smears, and we are truly confident that LBC can improve public health strategies aimed at reducing cervical lesions through prevention programs.

The Application of Classification and Regression Trees for the Triage of Women for Referral to Colposcopy and the Estimation of Risk for Cervical Intraepithelial Neoplasia: A Study Based on 1625 Cases with Incomplete Data from Molecular Tests

OBJECTIVE

Nowadays numerous ancillary techniques detecting HPV DNA and mRNA compete with cytology; however no perfect test exists; in this study we evaluated classification and regression trees (CARTs) for the production of triage rules and estimate the risk for cervical intraepithelial neoplasia (CIN) in cases with ASCUS+ in cytology.

STUDY DESIGN

We used 1625 cases. In contrast to other approaches we used missing data to increase the data volume, obtain more accurate results, and simulate real conditions in the everyday practice of gynecologic clinics and laboratories. The proposed CART was based on the cytological result, HPV DNA typing, HPV mRNA detection based on NASBA and flow cytometry, p16 immunocytochemical expression, and finally age and parous status.

RESULTS

Algorithms useful for the triage of women were produced; gynecologists could apply these in conjunction with available examination results and conclude to an estimation of the risk for a woman to harbor CIN expressed as a probability.

CONCLUSIONS

The most important test was the cytological examination; however the CART handled cases with inadequate cytological outcome and increased the diagnostic accuracy by exploiting the results of ancillary techniques even if there were inadequate missing data. The CART performance was better than any other single test involved in this study.

The role of liquid-based cytology and ancillary techniques in pleural and pericardic effusions: an institutional experience

BACKGROUND

Fine-needle aspiration cytology (FNAC) of serous membrane effusions may fulfil a challenging role in the diagnostic analysis of both primary and metastatic disease. From this perspective, liquid-based cytology (LBC) represents a feasible and reliable method for empowering the performance of ancillary techniques (ie, immunocytochemistry and molecular testing) with high diagnostic accuracy.

METHODS

In total, 3171 LBC pleural and pericardic effusions were appraised between January 2000 and December 2013. They were classified as negative for malignancy (NM), suspicious for malignancy (SM), or positive for malignancy (PM).

RESULTS

The cytologic diagnoses included 2721 NM effusions (2505 pleural and 216 pericardic), 104 SM effusions (93 pleural and 11 pericardic), and 346 PM effusions (321 pleural and 25 pericardic). The malignant pleural series included 76 unknown malignancies (36 SM and 40 PM effusions), 174 metastatic lesions (85 SM and 89 PM effusions), 14 lymphomas (3 SM and 11 PM effusions), 16 mesotheliomas (5 SM and 11 SM effusions), and 3 myelomas (all SM effusions). The malignant pericardic category included 20 unknown malignancies (5 SM and 15 PM effusions), 15 metastatic lesions (1 SM and 14 PM effusions), and 1 lymphoma (1 PM effusion). There were 411 conclusive immunocytochemical analyses and 47 molecular analyses, and the authors documented 88% sensitivity, 100% specificity, 98% diagnostic accuracy, 98% negative predictive value, and 100% positive predictive value for FNAC.

CONCLUSIONS

FNAC represents a primary diagnostic tool for effusions and a reliable approach with which to determine the correct follow-up. Furthermore, LBC is useful for ancillary techniques, such as immunocytochemistry and molecular analysis, with feasible diagnostic and predictive utility.

Expression of PTEN in endometrial liquid-based cytology

OBJECTIVES

Endometrial cytology offers a reliable alternative to biopsy in endometrial cancer detection and it may be useful in obtaining material to study prognostic and predictive markers. Over the years, new sampling devices have been developed. Molecular alterations in endometrial cancers were previously described using formalin-fixed paraffin-embedded tissues with particular attention, in endometrioid carcinomas, to the PTEN-PI3K pathway. PTEN evaluation could be useful in endometrial carcinomas for selecting patients for target therapies.

STUDY DESIGN

We studied 51 endometrial samples collected using the Endogyn device and 71 obtained with the Endoflower dispositive device, and processed using liquid-based cytology. Most of the cases were matched with a corresponding histological biopsy. The overall accuracy of Endoflower was 100%. Immunohistochemistry (IHC) and immunocytochemistry (ICC) for PTEN were performed using monoclonal antibody 6H2.1 from DAKO.

RESULTS

The IHC showed PTEN-null glands in 4 cases. The same cancers were negative in ICC. Among the 10 carcinomas on cytology, PTEN-null glands were found in 1 case. All the normal endometrium control cases were positive in cytology and histology.

CONCLUSIONS

Our results suggest that endometrial devices provide useful material for the diagnosis and evaluation of PTEN expression.

Cytology specimens offer an effective alternative to formalin-fixed tissue as demonstrated by novel automated detection for ALK break-apart FISH testing and immunohistochemistry in lung adenocarcinoma

BACKGROUND

Minimally invasive sampling by cytology or core needle biopsy often provides an initial diagnosis for treatment in patients with lung nodules. From these limited specimens, multiple molecular studies are frequently requested. Current guidelines from the US Food and Drug Administration recommend using formalin-fixed paraffin-embedded tissue sections for the detection of anaplastic lymphoma kinase (ALK) gene rearrangement by fluorescence in situ hybridization (FISH). The authors compared alcohol-fixed and formalin-fixed cytology specimens using a novel automated detection for ALK rearrangements by FISH and immunohistochemistry (IHC).

METHODS

ALK FISH testing was performed on 129 lung adenocarcinomas from 71 cytology cases and 58 biopsy/resection specimens using Papanicolaou staining with integrated cytomorphology. IHC with the ALK D5F3 antibody was performed on cases with residual material (88 of 129 cases).

RESULTS

The mean age of the patients was 66 years; there were 62 women and 67 men. ALK gene rearrangement was present in 4% of cytology specimens (3 of 71 specimens) and 7% of surgical specimens (4 of 58 specimens). FISH in 13 cases was technically unsuccessful. Of the 7 FISH-positive cases, only 2 cytology cases (4%) and 2 surgical cases (6%) were found to be positive with the ALK antibody, demonstrating 80% concordance. The one case found to be negative for ALK by IHC demonstrated a variant rearrangement of the ALK 2p23 gene locus by FISH.

CONCLUSIONS

The results of the current study validate the usefulness of alcohol-fixed and/or formalin-fixed cytology specimens for ALK rearrangement by a novel automated FISH method. IHC using the D5F3 antibody for ALK is specific in this limited cohort. The authors also demonstrated that alcohol-fixed cytology specimens can be used for ALK rearrangement by automated FISH, alone or in conjunction with IHC.

BRAF(V600E) assessment by pyrosequencing in fine needle aspirates of thyroid nodules with concurrent Hashimoto's thyroiditis is a reliable assay

Detection of BRAF mutation in cytology specimens has been proposed as a diagnostic adjunctive tool in evaluation of thyroid nodules with indeterminate cytology findings. Concurrent papillary thyroid carcinoma and Hashimoto's thyroiditis (HT), a disease characterized by thyroid lymphocytic infiltration, is a frequent occurrence. A large lymphocytic infiltrate might reduce the sensitivity of methods employed to detect BRAF mutation in thyroid cytology specimens. To determine whether testing for BRAF mutational status in fine needle aspirates (FNA) is reliable also in the presence of HT lymphocytic infiltration, we assessed the BRAF status by direct sequencing and pyrosequencing in a series of FNAs with and without concomitant HT lymphocytic infiltration. We also performed the same assessment by pyrosequencing in the corresponding tissue samples. Pyrosequencing demonstrated to be more sensitive than direct sequencing. The percentage of mutant BRAF(V600E) alleles was higher in FNAs than in the corresponding tissues, probably because of the lower stromal contamination in FNA than in the sections. In the presence of lymphocytic infiltration, the percentage of mutant BRAF(V600E) alleles determined by pyrosequencing was higher in FNAs than in the corresponding tissue samples (P < 0.0001), indicating a minor lymphocytic contamination in FNA. The diagnostic value of BRAF(V600E) in inconclusive FNAs was not hampered by thyroid lymphocytic infiltration. These results indicate that BRAF(V600E) assessment by pyrosequencing is a reliable assay useful to refine inconclusive cytology of thyroid nodules also in the presence of concurrent HT.

Is liquid-based cytology the magic bullet for performing molecular techniques?

OBJECTIVE

The role of pathology has evolved from the first microscopic definitions of diseases by Virchow to the new concept of molecular cytopathology. The management of diseases is now a multidisciplinary approach with the translation of morphological, imagery and molecular findings to therapeutic protocols. Obtaining the most reliable diagnostic material is the essential part of the medical management of patients.

STUDY DESIGN

Here, we try to gain a concise insight into the available data regarding the role of cytology in the application of molecular techniques, focusing on cancer cytopathology.

RESULTS

Obtaining cytological material is now feasible by different methods, and in some cases it is the only possible approach to a lesion which is not easily accessible for tissue sampling. The methods of obtaining cytological material have evolved in recent years in parallel with rapid advances in high-throughput molecular techniques, opening new windows for the diagnosis and management of diseases.

CONCLUSIONS

Different kinds of cytological material are reliable for the application of molecular techniques. Cytological material obtained in a liquid base has advantages such as the better preservation of cytomorphological features and the use of the remaining liquid for nucleic acid extraction even after long storage and the application of molecular methods.

The nightmare of indeterminate follicular proliferations: when liquid-based cytology and ancillary techniques are not a moon landing but a realistic plan

OBJECTIVE

Thyroid nodules are a common finding in the general population, including both nonneoplastic and neoplastic entities. Fine-needle aspiration cytology (FNAC) is the first tool for evaluating thyroid nodules. In spite of its high diagnostic accuracy, 25% of nodules result in the category of follicular neoplasms (FN), with varying risk of malignancy and different management strategies.

STUDY DESIGN

The use of ancillary techniques is reshaping the practice of FNAC. These tools can significantly empower the morphological diagnosis and prognosis of thyroid nodules, allowing a more accurate prediction of the nature of the lesion. Several studies have underlined the role of single or multiple testing for the category of FN as strong indicators of cancer. Every cytological preparation can be used for the application of ancillary techniques but the introduction of liquid-based cytology (LBC) might facilitate the application.

RESULTS

Our experience involving an immunocytochemical panel made up of HBME-1 and galectin-3 pointed to an 81% overall diagnostic accuracy in discriminating between low and high risk of malignancy in FN.

CONCLUSIONS

The application of these techniques on LBC represents an adjunct to the morphological evaluation of FN. They represent a critical and challenging, but also a feasible, tool in the preoperative diagnoses, allowing specific prognostic and predictive details regardless of the cytological preparation. © 2014 S. Karger AG, Basel.

Detection of common and less frequent EGFR mutations in cytological samples of lung cancer

OBJECTIVE

Lung cancer represents the leading cause of cancer death. EGFR mutations, detected in 10-40% of lung adenocarcinomas, are an essential key to therapeutic management. EGFR-activated mutations comprise mainly deletions in exon 19 and point mutations in exon 21. Although histology is the traditional method of detection, we investigated the role of cytology in EGFR mutations.

STUDY DESIGN

A total of 774 lung cancers were studied for EGFR mutations (676 histological and 98 cytological samples), including 424 adenocarcinomas, 326 non-small cell lung carcinomas not otherwise specified, and 24 squamous cell carcinomas.

RESULTS

We had a total of 164 (21.2%) cases of mutations. Common mutations were short in-frame deletions in exon 19 (53.7%) and single-nucleotide substitutions in exon 21 (34.1%); less frequent mutations included single-nucleotide substitutions in exon 18 (3.7%) and in-frame insertions/deletions in exon 20 (8.5%). Histologically, EGFR mutations in exons 19 and 21 occurred in 19.4% and in exons 18 and 20 in 2.2%, while the rates cytologically were 13.3% for exons 19 and 21 and 5.1% for exons 18 and 20.

CONCLUSIONS

The sensitivity for the detection of EGFR mutations in cytological samples overlaps histology, so the use of cytological material constitutes an adequate approach for treatment selection in patients with locally advanced or metastatic lung cancer.

The cytologic category of oncocytic (Hurthle) cell neoplasm mostly includes low-risk lesions at histology: an institutional experience

DESIGN

The cytological diagnosis of oncocytic/Hurthle cell neoplasms (OCN) represents a challenge with which cytopathologists face up to in their practice. The majority of these lesions undergo surgery for a definitive characterization of the nature mainly due to their more aggressive behavior than other malignant follicular lesions. In this study, we aimed at the evaluation of the effective malignant rate in a large cohort of OCNs.

METHODS

From January 2008 to December 2011, we analyzed 150 cyto-histological OCNs and 64 benign oncocytic/Hurthle lesions (BOL). Both groups of patients were analyzed for clinical and cyto-histological parameters. All the nodules were sampled under sonographic guidance and processed with the liquid-based cytological method.

RESULTS

In agreement with literature, we found a significant correlation only with female gender in both OCN (P=0.0160) and BOL groups. The 64 BOLs were histologically diagnosed as 15 Hashimoto thyroiditis (HT), 45 hyperplastic nodules in HT, and four papillary thyroid carcinomas (PTC, 6.2%). The 150 OCNs resulted in 141 (94%) oncocytic adenomas and nine (6%) malignant lesions. The latter group included five oncocytic carcinomas (OCC), three oncocytic variants of PTC, and one macrofollicular PTC featured by mild nuclear clearing with a dispersive cellular pattern. The malignant rate was respectively 6.2% in BOLs without any OCC whereas 3.3% OCC diagnosed in the OCN category.

CONCLUSIONS

Our OCNs mostly resulted in histological adenomas with a lower rate of malignancy than in other series. Some morphological parameters (nuclear clearing, dysplasia, and dispersive cellular pattern) might be helpful in stratifying OCN patients into different risks of malignancy.

The significance of augmented high-grade squamous intraepithelial lesion detection on pap test examination: partial results from the RODEO study team

OBJECTIVE

This study sought to ascertain the significance of augmented high-grade squamous intraepithelial lesion (HSIL) detection by Pap test using both conventional smear and liquid-based cytology (LBC) in a high-risk population.

STUDY DESIGN

We conducted a direct-to-vial study to compare the diagnostic performance of Pap smear versus LBC in a high-risk population of women referred for colposcopy at a gynecologic ambulatory clinic at the Barretos Cancer Hospital in Brazil during 2011.

RESULTS

The detection of both low-grade squamous intraepithelial lesions (LSILs) and HSILs was significantly greater (p = 0.04 and p = 0.033, respectively) in the LBC arm [84 LSIL cases (5.7%) and 148 HSIL cases (10.1%)] than in the conventional smear arm [66 LSIL cases (4.1%) and 126 HSIL cases (7.9%)]; however, no differences were found for invasive squamous carcinoma or adenocarcinoma (p = 0.678). Of 3,071 women who were examined cytologically (1,604 conventional preparations and 1,467 LBC) and colposcopically, biopsies were available for 279 conventional preparations (17.6%) and 325 LBC preparations (22.2%). No significant differences were found between the methods with respect to diagnostic performance.

CONCLUSION

LBC was significantly superior to conventional smears for the detection of LSILs and HSILs, but these results did not influence biopsy confirmation. Both methods showed similar performances with high positive predictive values but very low sensitivities.

Asymptomatic hematuria associated with urinary polyomavirus infection in immunocompetent patients

Unlike the case for immunodeficient patients, little is known about polyomavirus (PV) infection in immunocompetent patients. PV infection in immunocompetent individuals has been reported sporadically, but little is known about asymptomatic hematuria. To determine the clinical significance and prevalence of urinary PV infection in immunocompetent patients, a total of 95 individuals admitted to Seoul St. Mary's hospital were investigated. Sixty-four patients were enrolled for evaluation of asymptomatic hematuria, and 31 healthy individuals served as controls. Clinical screening for PV infection was performed by urine cytology analysis by liquid-based preparation and urine RT-PCR for BK virus (BKV) and JC virus (JCV), respectively. The average age of the patients in the PV(+) - and PV(-) -groups with asymptomatic hematuria were 60 years and 46 years, respectively. Urine cytology analysis revealed decoy cells in 37/64 hematuria patients (38.9%), but not in healthy controls. They were more prevalent in male patients. Eighty-two patients (86.3%) had PV viruria, viz., 54/64 patients in the hematuria group and 28/31 in the control group. Interestingly, 28/31 (90.3%) cases in the healthy control group were positive for PV viruria, which exceeded the number in the hematuria group (84.4%). PV viruria was associated primarily with JCV, rather than BKV. PV viruria, including JCV viruria, correlated with urine decoy cells and increased age. In conclusion, urinary PV infection is common in immunocompetent patients with asymptomatic hematuria and is age-related. These data may provide an insight into the pathogenesis and future treatment of asymptomatic hematuria associated with urinary PV infection in immunocompetent patients.

Diagnostic and prognostic value of immunocytochemistry and BRAF mutation analysis on liquid-based biopsies of thyroid neoplasms suspicious for carcinoma

OBJECTIVE

In the field of fine-needle aspiration cytology, the category of suspicious for malignancy (SM) thyroid lesions, that bears 55-85% risk of malignant histology, is a challenging topic in which morphology alone is not always able to make a correct diagnosis. Recently, immunocytochemistry (ICC) has been referred to as helpful in differentiating low- and high-malignant risk lesions and BRAF activating mutations have been identified in a significant amount of papillary thyroid carcinomas (PTC). The introduction of the liquid-based cytology (LBC) may simplify the application of these techniques to thyroid cytology.

DESIGN

Our aim is to evaluate the diagnostic and prognostic role of both ICC and BRAF mutation for the SM category on LBC.

METHODS

From October 2010 through June 2011, 113 LBC cytological cases (including 37 SM and 76 PTC) underwent surgery. All cases were studied for BRAF mutation and ICC.

RESULTS

ICC resulted positive in 26 (86.6%) histologically malignant SM with 15 of which (40.5%) expressing a BRAF mutation. Overall, 63 cases showed a BRAF mutation resulting in PTC. Concerning the prognostic role of BRAF mutation for the two categories, we reported a significant correlation with multifocality, nodal involvement and extra-capsular invasion (P<0.0001).

CONCLUSIONS

Special techniques such as ICC and molecular markers might be successfully carried out on LBC-processed material. For both categories, ICC is more sensitive whereas BRAF analysis is an interesting support due to its high specificity adding a prognostic value in both SM and PTCs.

Identification of women for referral to colposcopy by neural networks: a preliminary study based on LBC and molecular biomarkers

Objective of this study is to investigate the potential of the learning vector quantizer neural network (LVQ-NN) classifier on various diagnostic variables used in the modern cytopathology laboratory and to build an algorithm that may facilitate the classification of individual cases. From all women included in the study, a liquid-based cytology sample was obtained; this was tested via HPV DNA test, E6/E7 HPV mRNA test, and p16 immunostaining. The data were classified by the LVQ-NN into two groups: CIN-2 or worse and CIN-1 or less. Half of the cases were used to train the LVQ-NN; the remaining cases (test set) were used for validation. Out of the 1258 cases, cytology identified correctly 72.90% of the CIN-2 or worst cases and 97.37% of the CIN-1 or less cases, with overall accuracy 94.36%. The application of the LVQ-NN on the test set allowed correct classification for 84.62% of the cases with CIN-2 or worse and 97.64% of the cases with CIN-1 or less, with overall accuracy of 96.03%. The use of the LVQ-NN with cytology and the proposed biomarkers improves significantly the correct classification of cervical precancerous lesions and/or cancer and may facilitate diagnosis and patient management.

Molecular alterations in endometrial archived liquid-based cytology

Endometrial cancer is one of the most common gynecological malignancy worldwide and its prevalence is increasing. The introduction of liquid-based cytology (LBC) and endoflower dispositive in routine practice gives the possibility to examine endometrial cells by cytological diagnosis and may also release the opportunity to study molecular alterations, in endometrioid type cancer in which carcinogenesis is well known. We gathered 72 cases of endometrial LBC samples and corresponding formalin-fixed paraffin-embedded (FFPE) blocks, collected from 2004 to 2010. DNA was isolated from both samples using standard protocols. DNA quality and quantity were assessed using Nanodrop and BIOMED2 multiplex PCR. Mutations in exon 5 of PTEN and exon 20 of PI3K were studied using Sanger sequencing. DNA with good quality and amount was isolated from 67/72 FFPE cases. In these samples, two cases were found to harbor mutations in exon 5 of PTEN. No PI3K mutations were identified. LBC samples were then assessed to verify the concordance with the FFPE DNA results. The results obtained were concordant, that is the wild type cases in FFPE were also wild type in LBC and vice versa for the mutated case. Unfortunately, the second case of mutation in PTEN could not be confirmed in LBC due to low amount of DNA obtained. Detection of molecular alterations in LBC will open a new era for the detection in asymptomatic women of precursor lesions that could evolve into cancer and for endometrial cancer diagnosis and screening in selected high-risk women.

Immunocytochemistry with cytokeratin 19 and anti-human mesothelial cell antibody (HBME1) increases the diagnostic accuracy of thyroid fine-needle aspirations: preliminary report of 150 liquid-based fine-needle aspirations with histological control

BACKGROUND

Thyroid nodules are relatively common (7% of the population) but are malignant in only 5%-10% of cases. Fine-needle aspiration (FNA) to detect cancer can have > 90% sensitivity but only 50%-65% specificity because of false-positive results, which necessitates surgical controls. We aimed to assess the diagnostic accuracy of immunocytochemistry (ICC) of thyroid FNA to improve its sensitivity and specificity.

METHODS

We prospectively collected 2038 thyroid FNAs, of which 1397 were FNA biopsies with liquid-based cytology (Thin-Prep-Hologic®). ICC with cytokeratin 19 and HBME1 antibodies (Dako® A/S) was used for all malignant cases and cases of atypical cells of undetermined significance (AUS), follicular neoplasm (FN), and nodules suspicious for malignancy-papillary thyroid carcinoma (SM-PTC) as well as some benign cases (abnormal features on radiography or benign on secondary FNA). ICC results were defined as "non-contributory," "favoring benign," "favoring malignant," or "indeterminate." Results for 150 cases were compared with histological controls for diagnostic accuracy.

RESULTS

Of these 150 cases ICC was helpful for benign or malignant triage of 48 cases of AUS, FN, and SM-PTC (42% of these lesions). Six (4%) ICC results were false positive (favoring malignant with benign histology) but none were false negative (favoring benign with malignant histology). Results for indeterminate cytological cases favored malignant or benign disease with sensitivity, specificity, and negative and positive predictive values of 100%, 85.2%, 100%, and 86.2%, respectively.

CONCLUSIONS

ICC of thyroid FNAs with cytokeratin 19 and HBME1 antibodies can reduce the false-positive and false-negative results of single morphological analyses. It can increase the sensitivity and specificity of diagnosis, thus improving diagnostic accuracy and reducing the need for surgical controls.

Follicular thyroid neoplasms can be classified as low- and high-risk according to HBME-1 and Galectin-3 expression on liquid-based fine-needle cytology

DESIGN

Fine-needle aspiration biopsy (FNAB) is the most reliable diagnostic tool in the diagnosis of thyroid nodules. A cytologic diagnosis of follicular neoplasm with atypical cells of undetermined significance (FN/AUS) implies that the selection of patients between surgery and follow-up is difficult. In this setting immunocytochemical stainings might be helpful. The efficacy of a panel made up of HBME-1 and Galectin-3 antibodies is evaluated in cases processed by liquid-based cytology (LBC).

METHODS

Out of 7091 thyroid FNAB processed by LBC method, 120 cases undergoing surgery successively were selected. These cases were classified as benign lesion (BL, eight cases), FN, including the ACUS category of the Bethesda classification (FN/AUS, 50 cases), suspicious for malignancy (SM, 59 cases), and malignant neoplasm (MN, three cases). Immunostains for HBME-1 and Galectin-3 were carried out on the LBC slides.

RESULTS

All MN and BL were histologically confirmed. FN/AUS and SM showed a malignancy risk of 24 and 72.9% respectively. The complete immunocytochemical panel was positive in 83.3% of the cases resulting in malignancy and negative in 87.5% of cases resulting in benign histology. Among the FN/AUS, the complete positive immunocytochemical panel was detected in 76.9% of cases resulting as malignant and the complete negative immunocytochemical panel was observed in 96.8% of cases resulting as benign at histology.

CONCLUSIONS

The expression of HBME-1 and Galectin-3 in cases classified as FN/AUS on LBC-processed FNABs can effectively distinguish lesions, which need immediate surgery (high risk or FNH or Thy 3h) from those which can be followed-up (low risk or FNL or Thy 3l).

EGFR gene status in cytological samples of nonsmall cell lung carcinoma: controversies and opportunities

BACKGROUND

In nonsmall cell lung cancer (NSCLC), the development and clinical application of tyrosine kinase inhibitors (TKIs) targeting the epidermal growth factor receptor (EGFR) has required the investigation of EGFR status by gene copy number and/or mutation analysis. This review aimed to present the current knowledge of the use of cytological specimens for EGFR testing in lung cancer.

METHODS

A systematic computerized search was performed of the MEDLINE(R) and EMBASE databases to identify articles reporting the use of cytological samples for determining EGFR status in NSCLC.

RESULTS

Data were extracted from 30 original articles. An additional 19 reviews, consensus statements, and editorials were selected from 175 retrieved papers. Different techniques using cell blocks, scraped cells from archival slides, and fresh cells have shown promising results and include fluorescent in situ hybridization (FISH), direct sequencing, and quantitative polymerase chain reaction (PCR), with similar or higher accuracy and sensitivity than surgical specimens. Preservation and quality of the extracted DNA seem to matter more than the actual number of tumor cells present in the samples. However, major issues still reside in the amount of material, the interference from background non-neoplastic cells, and standardization of parameters for cytological samples.

CONCLUSIONS

This analysis provided evidence that cytological material is suitable for detecting EGFR status using several different methodologies and preparations. New prospective, clinical studies are encouraged for collection and handling of cytological samples as well as for validation of novel techniques in large cohorts.

Preservation of fine-needle aspiration specimens for future use in RNA-based molecular testing

BACKGROUND

The application of ancillary molecular testing is becoming more important for the diagnosis and classification of disease. The use of fine-needle aspiration (FNA) biopsy as the means of sampling tumors in conjunction with molecular testing could be a powerful combination. FNA is minimally invasive, cost effective, and usually demonstrates accuracy comparable to diagnoses based on excisional biopsies. Quality control (QC) and test validation requirements for development of molecular tests impose a need for access to pre-existing clinical samples. Tissue banking of excisional biopsy specimens is frequently performed at large research institutions, but few have developed protocols for preservation of cytologic specimens. This study aimed to evaluate cryopreservation of FNA specimens as a method of maintaining cellular morphology and ribonucleic acid (RNA) integrity in banked tissues.

METHODS

FNA specimens were obtained from fresh tumor resections, processed by using a cryopreservation protocol, and stored for up to 27 weeks. Upon retrieval, samples were made into slides for morphological evaluation, and RNA was extracted and assessed for integrity by using the Agilent Bioanalyzer (Agilent Technologies, Santa Clara, Calif).

RESULTS

Cryopreserved specimens showed good cell morphology and, in many cases, yielded intact RNA. Cases showing moderate or severe RNA degradation could generally be associated with prolonged specimen handling or sampling of necrotic areas.

CONCLUSIONS

FNA specimens can be stored in a manner that maintains cellular morphology and RNA integrity necessary for studies of gene expression. In addition to addressing quality control (QC) and test validation needs, cytology banks will be an invaluable resource for future molecular morphologic and diagnostic research studies.

Liquid-based FNAC of the thyroid: a 4-year survey with SurePath

BACKGROUND

The aims of this study were to analyze cytomorphological features of Tripath PREP (BD SurePath, Burlington, NC) preparations in thyroid nodules and to examine adequacy and accuracy of SurePath and frozen sections for both clinical outcome and histological diagnosis when applicable.

METHODS

Gathered during a period of 4 years, 712 SurePath specimens of the thyroid were included. Histological (n = 207) or clinical follow-up (n = 505) was available in all cases. During the same period, 253 frozen sections of surgical thyroid resection specimens were also assessed. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated.

RESULTS

Sensitivity was 77% for SurePath and 29% for frozen section; specificity was 81% for SurePath and 100% for frozen section; accuracy was 80% for SurePath and 90% for frozen section. One hundred seventy-eight (25%) SurePath patients were considered unsatisfactory for diagnosis. In this study, sensitivity, specificity, and accuracy were comparable for SurePath and other reported results of liquid-based thyroid cytology. Presence of free colloid or pure cystic changes favored a benign diagnosis. Cellular smears with nuclear atypia of papillary carcinoma allowed an overt diagnosis of malignancy.

CONCLUSIONS

The authors concluded that SurePath is a reliable technique for assessment of thyroid nodules and offers the advantage of easy identification of colloid and atypical nuclei. Supplementary frozen section analysis should be limited to an FNAC diagnosis of suspicious for papillary carcinoma.

Urine and bladder washing cytology for detection of urothelial carcinoma: standard test with new possibilities

Background

Light microscopic evaluation of cell morphology in preparations from urine or bladder washing containing exfoliated cells is a standard and primary method for the detection of bladder cancer and also malignancy from other parts of the urinary tract. The cytopathologic examination is a valuable method to detect an early recurrence of malignancy or new primary carcinoma during the follow-up of patients after the treatment of bladder cancer.

Conclusions

Characteristic cellular and nuclear signs of malignancy indicate invasive or in situ urothelial carcinoma or high-grade papillary urothelial carcinoma. However, low sensitivity of the method reflects the unreliable cytopathologic diagnosis of low-grade urothelial neoplasms as cellular and nuclear signs of malignancy in these neoplasms are poorly manifested. Many different markers were developed to improve the diagnosis of bladder carcinoma on urinary samples. UroVysion™ test is among the newest and most promising tests. By the method of in situ hybridization one can detect specific cytogenetic changes of urothelial carcinoma.

Detection of SYT and EWS gene rearrangements by dual-color break-apart CISH in liquid-based cytology samples of synovial sarcoma and Ewing sarcoma/primitive neuroectodermal tumor

To improve cytologic diagnostic accuracy for translocation-associated sarcomas, we explored dual-color break-apart (dc) chromogenic in situ hybridization (CISH) on liquid-based cytology (LBC) samples of 2 prototypic sarcomas: synovial sarcoma (SS) and Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET). LBC samples of 10 cases of SS and 9 cases of ES/PNET were subjected to dc-CISH using probes for the specifically rearranged genes in each tumor entity: SYT in SS and EWS in ES/PNET. Rearranged SYT was successfully detected in all SSs but not in any ES/PNETs. In contrast, EWS rearrangement was identified in all ES/PNETs but not in any SSs. These results were validated by dc-fluorescence in situ hybridization and reverse transcription-polymerase chain reaction. dc-CISH on LBC samples is a reliable modality to detect gene rearrangements in sarcomas. This system has a clear advantage over other methods, enabling simultaneous visualization of the genetic abnormality and well-preserved, nonoverlapping cytomorphologic features with clear background under bright-field microscope.

BRAFV600E mutation analysis in fine-needle aspiration cytology specimens for evaluation of thyroid nodule: a large series in a BRAFV600E-prevalent population

BACKGROUND

The BRAFV600E mutation is highly specific to papillary thyroid carcinoma. A test for this mutation may increase the diagnostic accuracy of fine-needle aspiration cytology (FNAC), especially in a BRAFV600E mutation-prevalent population.

METHODS

This prospective study enrolled 1074 patients with thyroid nodules who underwent both FNAC and BRAFV600E mutation analysis by dual-priming oligonucleotide (DPO)-based multiplex PCR in FNA specimens.

RESULTS

The ancillary test for BRAFV600E significantly improved the sensitivity of FNA procedure, from 67.5% with FNAC alone to 89.6% with FNAC and the DPO-based multiplex PCR analysis combined. Diagnostic accuracy increased from 90.9 to 96.6%. Nine cases of papillary thyroid carcinoma were detected only by BRAFV600E mutation analysis. Unexpectedly, the preoperative DPO-based multiplex PCR produced five false-positive results, which surgery showed to represent benign nodules.

CONCLUSIONS

Molecular testing for the BRAFV600E mutation in FNA thyroid nodule specimens increases diagnostic value when applied in a BRAFV600E mutation-prevalent population. However, when using this potentially powerful technique, we must consider both its strengths and its weaknesses.

Usefulness of oral cytopathology in the diagnosis of infectious diseases

In recent years, the incidence of oral opportunistic infections has increased, partly due to the widespread implementation of organ and bone marrow transplantation and the increase in the prevalence of human immunodeficiency virus (HIV) infection. Cytology can be used as a rapid, inexpensive and simple routine procedure in diagnosing infectious diseases of the mouth. Moreover, ancillary methods can be applied to cytological samples, increasing the specificity and sensitivity for the diagnosis of infectious diseases. This review describes the cytopathological features of the main viral, fungal, bacterial and parasitic infections of the mouth. Cytological techniques of specimen collection, identification of infectious agents by cytomorphological approaches and ancillary methods, and diagnostic pitfalls will be discussed.