Review of the impact of the International System for Serous Fluid Cytopathology.

The International System for Reporting Serous Fluid Cytology (TIS) has been proposed by an expert working team composed of the International Academy of Cytology and the American Society of Cytopathology, following an international survey. Since its introduction, the TIS has gained worldwide acceptance, and this review aims to assess its global impact. A literature search revealed 25 studies which have presented data on the impact of the TIS. Most of them provide data, including risk of malignancy (ROM) for each diagnostic category, separately for pleural, peritoneal and pericardial effusions, while a few do not separate them. A few studies focus on specific diagnoses like mesothelioma on specific types of fluids or more specific issues like the optimal fluid volume for cytology or interobserver variability. A synopsis of the data from the literature search is presented in four tables. The ROM assessment is discussed, as well as interobserver variability and the use of ancillary diagnostic immunochemistry. In conclusion, our review of the published data suggests that the TIS is a valid classification scheme that has been widely accepted by pathologists globally, is highly reproducible and makes a valuable contribution to clinical therapeutic management.

[Cytology of body cavity fluids - established methods and new developments]. / Zytologie der Körperhöhlenergüsse ­ Bewährtes und neue Entwicklungen.

BACKGROUND: Body cavity fluids are among the most frequently examined samples in cytology. Cytomorphology is supplemented by additive testing. An international system of terminology and classification has been recently presented. OBJECTIVES: Cytopreparation and staining techniques as well as some exemplary morphological patterns are presented. "The International System for Serous Fluid Cytopathology" (TIS) is briefly presented. MATERIALS AND METHODS: Pleural effusion, pericardial effusion, and ascites: special technical issues, immunocytochemistry, molecular diagnostics, and reporting system issues are discussed. RESULTS: Body cavity fluids are important samples that provide significant information. Additive testing is established for routine use. The form and structure of reports is widely divergent in practical use. DISCUSSION: A reporting system for serous fluid cytopathology that is easily applied and recognized internationally is highly desirable. TIS is a valuable approach to this goal.

[Cytology of primary lung cancer]. / Zytologie der primären Lungenkarzinome.

BACKGROUND: In addition to histological examinations, cytological samples are also being evaluated with increasing frequency for the diagnosis of lung carcinoma. OBJECTIVES: Possible applications of and techniques for cytological examinations are presented. Typical morphologies of primary lung cancer and metastatic disease are shown. MATERIAL AND METHODS: Samples were obtained during bronchoscopy, serous effusion fluid, and fine-needle aspiration cytology. Special technical features of the cytological samples are discussed. Cytomorphology of pulmonary adenocarcinoma, squamous-cell carcinoma, and small-cell lung carcinoma are shown. RESULTS: There are clear-cut diagnostic criteria for the main subtypes of primary lung carcinoma. CONCLUSIONS: Cytological examination is a valuable addition to histology for lung carcinoma diagnostics.

[Molecular diagnostics of cytological specimens]. / Molekularpathologische Diagnostik an zytologischen Präparaten.

For lung carcinomas with certain molecular genetic alterations of the ALK, BRAF or EGFR gene, there are targeted therapies that are also approved as first-line therapy. Often, only limited sample material from biopsies is available for molecular pathological testing. In some cases, biopsies with standard and immunohistochemical staining have no or too low tumor content to be used for PCR-based examinations or fluorescence in situ hybridization (FISH) analyses. In such cases, cytological preparations such as bronchus brush smears, transbronchial needle aspiration (TBNA), bronchial lavage, puncture smears from lymph node or peripheral metastases, pleural effusion, ascites, and pericardial effusion can be used. Standard stainings such as HE, Pappenheim, and Papanicolaou as well as immunohistological preparations can be used after morphological analysis and confirmatory diagnosis in order to extract DNA from them or to use them for FISH analysis. A cytopathologist marks the tumor cell areas on the slide beforehand. It is only possible to dissect these areas and extract DNA if the proportion of tumor cells is sufficiently high. In order to carry out a FISH analysis with the cytological preparations, the cytopathologist must draw in areas as small as possible with more than 100 tumor cells. Already stained sections are destained before the hybridization reaction. The aim is to achieve comprehensive diagnostics even with limited starting material and to avoid re-biopsies. Between 2016 and July 2019, 1711 next generation sequencing (NGS) and FISH analyses were performed on cytological preparations at the Department of Pathology of the University Hospital of Cologne. The success rate of 85.9% for NGS examinations was slightly higher than the success rate of 82.8% for FISH analyses.

Bronchoscopic Brushing from Central Lung Cancer-Next Generation Sequencing Results are Reliable.

The role of bronchoscopic brushing for tumor detection and molecular testing in central lung cancer is unclear. In this study, 50 consecutive subjects with suspected central lung cancer underwent bronchoscopic brushing (31 males, median age 70, 5 never smokers). Histological results were: NSCLC/SCLC/low-grade-NET/granulation tissue in 36/8/2/4 cases. Next generation sequencing (NGS) was feasible in 62% of tumor-positive brush smear samples. In 78% of these cases, NGS displayed identical results compared to histology samples, in 22% NGS from brush smears detected specific mutations, whereas DNA quality from forceps biopsy was insufficient for NGS analysis. Sensitivity, specificity, positive predictive value, negative predictive value of brush smear analysis were 66% (95% confidence interval 50-79), 100% (40-100), 100% (85-100), and 21% (7-46). For the combined analysis of brush smear, brush tip washing and sheath tube content sensitivity was slightly elevated at 69% (53-81). In central lung cancer, bronchoscopic brushing detects tumor cells in about two-third of cases and allows a decision for or against targeted therapy in the majority of tumor-positive cases on the basis of NGS analysis.

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.

Case Report: A Cryptosporidium infection in a patient with relapsed T-lymphoblastic lymphoma undergoing allogeneic stem cell transplantation.

Cryptosporidium infection is a rare cause of enterocolitis. In immunocompromised patients, cryptosporidiosis may lead to debilitating and life-threatening diarrhea and malabsorption, occasionally with multi-organ involvement. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) requires long-term immunosuppressive therapy, while cellular immunity is usually compromised due to intensive conditioning chemotherapy. Diarrhea in patients who underwent allo-HSCT may be a sign of an infection, but can also be the result of intestinal graft-versus-host disease (GvHD). Here, we describe the case of a patient who developed severe diarrhea following allo-HSCT for relapsed T-lymphoblastic lymphoma. Initially, GvHD was suspected and treatment was initiated accordingly. However, a colon biopsy showed signs of cryptosporide oocysts alongside only low-grade GvHD. Following molecular confirmation of the diagnosis of cryptosporidiosis, an intensive treatment regimen was started. Despite the severe clinical course, the patient recovered and was discharged with only residual symptoms.

Rapid remineralization of multiple disseminated bone lesions after high-dose cytarabine in a patient with isolated myeloid sarcoma.

Isolated myeloid sarcoma is a rare presentation of acute myeloid leukemia. There are limited data available concerning the prognostic relevance and the right treatment strategy for this clinical scenario. Here, we report a case of acute myeloid leukemia with extensive lesions and fractures in multiple bones in a 64-yr-old male patient. Remarkably, treatment with a high-dose cytarabine regimen led to rapid remineralization of all bone lesions and recovery of the patient's mobility within a few weeks. Thereby, surgical treatment and radiotherapy could be avoided, supporting the role of intensive induction and standard consolidation chemotherapy as first-line treatment for myeloid sarcoma.

The World Health Organization Reporting System for Lung Cytopathology.

The International Academy of Cytology has joined with the International Agency for Research on Cancer (IARC) to bring together a group of experts in lung cytopathology to develop a WHO Reporting System for Lung Cytopathology (WHO System). This WHO System defines five categories for reporting lung cytopathology, that is, "Insufficient"/"Inadequate"/"Non-diagnostic," "Benign," "Atypical," "Suspicious for malignancy," and "Malignant," each with a clear descriptive term for the category, a definition, a risk of malignancy and a suggested management algorithm. The key diagnostic cytopathology features of each of the lesions within each category have been established by consensus and will be presented more fully in a subsequent IARC e-book and published hard cover book.The WHO System provides the best practice application of ancillary testing, including immunocytochemistry and molecular pathology, and provides a review to guide sampling and processing techniques to optimize the handling and preparation of the cytopathology sample emphasizing the cytomorphological differential diagnosis to aid low-resourced settings. The authors recognize that local medical and pathology resources will vary, particularly in low- and middle-income countries, and have developed the WHO System to make it applicable worldwide based on cytomorphology with options for further diagnostic management of the patient.The online WHO System provides a direct link to the WHO Tumour Classification for Thoracic Tumours 5th Edition. It will raise the profile and use of cytopathology by increasing awareness of its current role and its potential role in the era of personalized medicine based on molecular pathology utilizing "small biopsies." Ultimately, the System will improve patient care and outcomes.This System aims to improve and standardize the reporting of cytopathology, facilitate communication between cytopathologists and clinicians and improve patient care. The System is based on the current role of lung cytopathology and synthesizes the existing evidence while highlighting areas requiring further research and the future potential role of lung cytopathology.

A brief review of the WHO reporting system for lung cytopathology.

The International Academy of Cytology has joined with the International Agency for Research on Cancer to bring together a group of experts in lung cytopathology to develop a WHO Reporting System for Lung Cytopathology (WHO System). This System aims to improve and standardize the reporting of cytopathology, facilitate communication between cytopathologists and clinicians, and improve patient care. The WHO System describes 5 categories for reporting lung cytopathology: 'Insufficient/Inadequate/Nondiagnostic', 'Benign', 'Atypical', 'Suspicious for malignancy', and 'Malignant', each one with a clear descriptive term, a definition, a risk of malignancy, and a suggested management algorithm. The key diagnostic cytopathologic features of each of the lesions within each category have been established by consensus through an Expert Editorial Board, who are also the authors of this review and selected for each reporting system and chosen based on their expertise in the field and/or diversity of geographical representation. Many other co-authors from around the world also contributed. The assignment of writing and editing responsibilities used the same model as that used for the WHO Classification of Tumours (https://whobluebooks.iarc.fr/about/faq/). The WHO System provides the best practice application of ancillary testing, including immunocytochemistry and molecular pathology, and guides in sampling and processing techniques to optimize the handling and preparation of specimens. The WHO System was created by the authors to be applicable globally and is based on cytomorphology with possibilities for additional diagnostic management of the patient. The authors are aware that local medical and pathology resources would differ, especially in low- and middle-income countries. The WHO Tumour Classification for Thoracic Tumors, Fifth Edition, is directly accessible through the online WHO System.

[Cytopathology and molecular diagnostics of non-small cell lung cancer (NSCLC)]. / Zytopathologie und molekulare Diagnostik von nichtkleinzelligen Lungenkarzinomen (NSCLC).

Cytological specimens from endobronchial aspirates and pleural effusions are frequently used materials in the diagnostics of non-small cell lung cancer (NSCLC). In the same way as histological samples from endobronchial and transbronchial biopsy material or computed tomography (CT)-guided needle biopsies, cytological specimens are eminently suitable for molecular and immunohistological biomarker diagnostics of NSCLC, provided optimal techniques and clear diagnostic algorithms are employed. This article presents the typical processing techniques and a scheme for biomarker analytics and discusses an optimal approach for comprehensive diagnostics of NSCLC. When cytological specimens are processed and used in this way, the analytics are equivalent to those from histopathological specimens. For a detailed and advanced description of cytological and molecular techniques on cytological specimens the reader is referred to our own review articles.

Prevalence of abnormal Pap smear results in inflammatory bowel disease: a prospective study.

PURPOSE: Development of malignancy is a pending threat for patients with inflammatory bowel disease (IBD). Aim of this study was to analyze cervical dysplasia and infection with human papilloma virus (HPV) in patients with IBD. METHODS: This was a prospective, single center cohort study in Germany. Consecutive IBD patients admitted to the Department of Gastroenterology were sent to Gynecology, where a questionnaire was answered and gynecological examinations including a smear for cytology and HPV were taken. Participants of a general screening program constituted controls. Descriptive statistics, 95% confidence intervals and odds ratios were calculated. RESULTS: A total of 101 patients were recruited of which 99 patients participated. Analysis showed a significant (p = 0.05) difference between the prevalence of abnormal smears in patients with (22%) and without (6%) immunosuppressive therapy, while the latter had cervical abnormalities comparable with healthy controls (5%). All immunosuppressants showed similarly high risks for abnormal smear results. Only 11/99 (11%) patients had positive high-risk HPV tests, which is comparable with general population. CONCLUSION: The prevalence of abnormal cervical smears is higher in IBD patients compared to healthy individuals, but the difference is confined to patients with IBD and immunosuppressive therapy. Annual screening is advisable.

COVID-19 pandemic impact on cytopathology practice in the post-lockdown period: An international, multicenter study.

BACKGROUND: In a previous worldwide survey, the authors showed a drastic reduction in the number of cytological specimens processed during the coronavirus disease 2019 "lockdown" period along with an increase in malignancy rates. To assess the continued impact of the pandemic on cytological practices around the world, they undertook a second follow-up worldwide survey collecting data from the post-lockdown period (2020). METHODS: Participants were asked to provide data regarding their cytopathology activity during the first 12 weeks of their respective national post-lockdown period (2020), which ranged from April 4 to October 31. Differences between the post-lockdown period and the corresponding 2019 period were evaluated, and the authors specifically focused on rates of malignant diagnoses. RESULTS: A total of 29 respondents from 17 countries worldwide joined the survey. Overall, a lower number of cytological specimens (n = 236,352) were processed in comparison with the same period in 2019 (n = 321,466) for a relative reduction of 26.5%. The overall malignancy rate showed a statistically significant increase (12,442 [5.26%] vs 12,882 [4.01%]; P < .001) during the same time period. Similar results were obtained if both malignancy and suspicious for malignancy rates were considered together (15,759 [6.58%] vs 16,011 [4.98%]; P < .001). CONCLUSIONS: The data showed a persistent reduction in the cytological specimen volume during the post-lockdown period (2020). However, the relative increase in the cytological workload in the late part of the post-lockdown is a promising finding of a slow return to normality.

Cytology samples and molecular biomarker testing in lung cancer-advantages and challenges.

This review presents an overview on molecular diagnostic in lung cancer using cytologic samples. Every patient with advanced non-small cell lung cancer (NSCLC) should be tested for targetable driver mutations and gene arrangements. If a mutation is found, this may open an option for targeted therapy. As most of the NSCLC patients in advanced stage of disease are no candidates for surgery, these tests have to be performed on small biopsies or cytology samples. The most common and treatable gene alterations should be tested in every patient: EGFR, ALK, ROS1. A growing number of other genetic changes with targetable mutations may become treatable in the near future. To find patients who might profit from inclusion into clinical studies, relevant additional markers may be tested in an appropriate context. Another important approach for treatment is immunotherapy of lung cancer, which is guided by status of PD-L1 expression on tumour cells. The use of cytology samples carries considerable advantages: often, DNA of high quality is extracted thus enabling easy and precise analysis, and samples may be easily obtained. In case of effusions, effusion fluid seldom is not aspirated for immediate patient relief, so no additional dedicated procedure is needed. Some challenges exist: If the tumour cell count is low, mutations with a low allelic frequency may be missed. In cellblocks formalin-induced DNA, damage may obviate any DNA analysis. In very cellular smears, FISH may be impossible due to massive overlapping of nuclei. Autofluorescence may impede FISH analysis. Although there is no real universal test for genomic profiling for lung cancer, the pathology laboratory must be prepared to offer different assays on different specimens in order to address turnaround time and optimise detections of difficult tumour alterations such as gene fusions. The data from the literature demonstrate that cytology show consistent results, and it is a good alternative for lung cancer molecular testing.

High sensitivity of PD-L1 analysis from pleural effusion in nonsmall cell lung cancer.

Background: Programmed cell death protein 1 (PD-1)/programmed cell death protein ligand 1 (PD-L1) immune checkpoint inhibitors have been approved for monotherapy of metastatic nonsmall cell lung cancer (mNSCLC) depending on tumour cells' PD-L1 expression. Pleural effusion is common in mNSCLC. The significance of immunocytochemistry PD-L1 analysis from pleural effusion samples is unclear. Aim: The aim of the study was to analyse the sensitivity regarding immunocytochemistry PD-L1 analysis of pleural effusion in NSCLC as compared to immunohistochemistry of pleural biopsies. Patients and Methods: Fifty consecutive subjects (17 female, median age 72.5 years, seven never-smokers) were enrolled in this prospective controlled two-centre study. Inclusion criteria were pleural effusion, suspected or known lung cancer, indication for pleural puncture and thoracoscopy, and written informed consent. Immunocytochemistry and immunohistochemistry PD-L1 analyses were performed with the Dako-PDL1-IHC-22C3pharmDx assay. Analysis for sensitivity, specificity, and positive and negative predictive value was performed for PD-L1 detection from pleural effusion. Results: 50 subjects underwent pleural puncture and thoracoscopy. Pathological diagnoses were lung cancer (48), lymphoma (1) and mesothelioma (1). Sensitivity, specificity, positive predictive value and negative predictive value of PD-L1-testing with expression ≥50% defined as positive were 100% (95% CI 46-100%), 63% (36-84%), 45% (18-75%) and 100% (66-100%), and with expression ≥1% defined as positive 86% (56-97%), 43% (12-80%), 75% (47-92%) and 60% (17-93%). Conclusion: PD-L1 analysis in tumour-positive pleural effusion samples shows a very high sensitivity and negative predictive value, especially regarding PD-L1 expression levels ≥50% (European Medicines Agency approval). Negative results are reliable and help in the decision against a first-line checkpoint inhibitor monotherapy. However, a 1% cut-off level (United States Food and Drug Administration approval) leads to a markedly lower negative predictive value, making other invasive procedures necessary (NCT02855281).

Current Topics and Practical Considerations of Cytology Practice in Lung Cancer: Reflexions from the Lung Symposium at the 42nd European Congress of Cytology, Malmö, 2019.

In June 2019, a lung symposium was held at the 42nd European Congress of Cytology in Malmö, Sweden. Due to the current importance of cytological samples in the diagnoses and molecular analysis to set up the utmost management of lung cancer patients, cytologists from different countries shared the experience of their institutions. The place of the cytological samples gains more and more importance on the potential long-term survival gain through personalized medicine and this harbors the improvement of the guidelines both in pathology and cytology field. In this symposium, the new 6-tiered reporting system for pulmonary cytology proposed by the Papanicolaou Society of Cytopathology and detailed cytomorphological approach to lung carcinoma including lookalike lesions and DNA- and RNA-based analysis of cytology material have been discussed. The cytopathologist plays a pivotal role in ensuring success of a correct triage for the cytology material to be sure of the adequacy and quality of the yield from the rapid on-site evaluation till the report which should encompass molecular profile in rational patient management.

Benign Thyroid Diseases: Are There Gender-Specific Differences for Diagnosis and Treatment of Nontoxic Thyroid Nodules? Results from a 4-Year Retrospective Analysis of an Endocrine Tumor Board.

INTRODUCTION: Benign nodular goiters are endemic in Germany and diagnostic thyroidectomy is one of the most frequent surgical procedures. Less than 10% result in a malignant finding which is a poor ratio in comparison to other European countries. There is a female preponderance in almost all thyroid pathologies according to the current literature but not much is known concerning gender-specific differences in thyroid nodules. OBJECTIVE: We aimed at finding gender-specific differences in diagnosis and treatment of nontoxic thyroid nodules and focused on preoperative workup as well as cytological and histological findings of patients with solitary and multinodular nontoxic goiters. METHODS: We retrospectively analyzed 392 cases out of 693 thyroid cases managed interdisciplinarily by the endocrine board of a university center between January 2015 and December 2018 (4 years). RESULTS: The combination of fine needle biopsy and interdisciplinary case discussion resulted in a rate of malignancy of 28.9% in patients undergoing surgery for solitary and multinodular nontoxic goiter. Although there was no significant gender-specific difference in the distributions and malignancy rates of Bethesda categories, male patients had a significantly higher malignancy rate of 40% in our collective (p = 0.04). CONCLUSIONS: Surgical treatment for male patients with suspicious hypofunctioning thyroid nodules should be favored. However, well-designed prospective studies are required to investigate gender-specific recommendations for the treatment of benign thyroid diseases in the future.

Combining biopsy tools improves mutation detection rate in central lung cancer.

In central exophytic lung cancer, the detection rate of oncogenic mutations and PDL1 positivity may be increased by combined sampling by forceps and EBUS-TBNA. The additional sampling of mediastinal lymph node and ctDNA may not be of additional benefit. https://bit.ly/2Ve41EF.

Global impact of the COVID-19 pandemic on cytopathology practice: Results from an international survey of laboratories in 23 countries.

BACKGROUND: To the authors' knowledge, the impact of the coronavirus disease 2019 (COVID-19) pandemic on cytopathology practices worldwide has not been investigated formally. In the current study, data from 41 respondents from 23 countries were reported. METHODS: Data regarding the activity of each cytopathology laboratory during 4 weeks of COVID-19 lockdown were collected and compared with those obtained during the corresponding period in 2019. The overall number and percentage of exfoliative and fine-needle aspiration cytology samples from each anatomic site were recorded. Differences in the malignancy and suspicious rates between the 2 periods were analyzed using a meta-analytical approach. RESULTS: Overall, the sample volume was lower compared with 2019 (104,319 samples vs 190,225 samples), with an average volume reduction of 45.3% (range, 0.1%-98.0%). The percentage of samples from the cervicovaginal tract, thyroid, and anorectal region was significantly reduced (P < .05). Conversely, the percentage of samples from the urinary tract, serous cavities, breast, lymph nodes, respiratory tract, salivary glands, central nervous system, gastrointestinal tract, pancreas, liver, and biliary tract increased (P < .05). An overall increase of 5.56% (95% CI, 3.77%-7.35%) in the malignancy rate in nongynecological samples during the COVID-19 pandemic was observed. When the suspicious category was included, the overall increase was 6.95% (95% CI, 4.63%-9.27%). CONCLUSIONS: The COVID-19 pandemic resulted in a drastic reduction in the total number of cytology specimens regardless of anatomic site or specimen type. The rate of malignancy increased, reflecting the prioritization of patients with cancer who were considered to be at high risk. Prospective monitoring of the effect of delays in access to health services during the lockdown period is warranted.

Usefulness of imprint and brushing cytology in diagnosis of lung diseases with flexible bronchoscopy.

BACKGROUND: To increase the diagnostic yield in pulmonary diseases, histopathology, imprint cytology and brushing cytology are assessed in combination during flexible bronchoscopy. However, the individual diagnostic discrimination of the three methods is unclear. METHODS: The authors performed the three sampling techniques in 102 consecutive patients with suspected pulmonary pathologies and compared the definitive diagnosis with those of histopathology, imprint and brushing cytology for their diagnostic values regarding evidence of malignancy. RESULTS: 33.3% of all histopathological specimens, 31.4% of all imprints and 26.5% of brush biopsy specimens were positive for malignancy. The values for sensitivities were 94% for histopathology, 89% for imprint cytology and 75% for brushing cytology, respectively. Although brushing cytology had limited sensitivity, in two cases a malignant lung tumour was only diagnosed from cytological examination of brushing. CONCLUSION: In conclusion, routine imprint cytology does not increase the diagnostic sensitivity, whereas routine brushing cytology should be used in combination with histopathology to obtain the highest diagnostic rate of yield.