Acta Cytologica最新文献

Background Lymphoepithelial carcinoma of the lung shows distinctive histologic features but its cytologic description is limited in the literature. This study reviews and compares a large cohort of lung and lymph node aspirates, bronchial, serous fluid, and sputum exfoliative cytology from histology-proven cases, aiming to detail diagnostic features and cytologic specimen types preferable for diagnosis of this entity. Methods Cytology specimens of patients with a histologic diagnosis of lymphoepithelial carcinoma on lung biopsy or resection were reviewed for cytomorphologic features associated with lymphoepithelial carcinoma, with comparison between cytologic specimen types performed. Results Totally 13 aspiration (7 lung and 6 lymph node) and 22 exfoliative (18 bronchial, 1 serous fluid and 4 sputum cytology) specimens were reviewed. The most common cytomorphologic features observed were macronucleoli (82.9%), marked nuclear membrane irregularity (82.9%) and naked tumor nuclei (74.3%). High cellular cohesion, presence of large tumor fragments, rich lymphoid background, and tumor-infiltrating lymphocytes, are also frequently seen (>60%). Lymphoid components, multinucleated tumor cells and large epithelial fragments were more commonly seen in aspirations compared to exfoliative specimens (p<0.05). Conclusion Distinctive morphological features of lymphoepithelial carcinoma of lung are reproducible on cytologic specimens. Qualitative nuclear features (macronucleoli, marked nuclear membrane irregularity and naked tumor nuclei) are the most consistently observed. Compared to exfoliative cytology, aspirated specimens show higher yield for diagnostic cytomorphologic features of lymphoepithelial carcinoma.

Background: The World Health Organization (WHO) Classification of Female Genital Tumours, Fifth Edition (2020), proposed a classification of uterine cervical glandular lesions according to whether they are associated with human papillomavirus (HPV) or not. The WHO recommends HPV genetic screening as an initial test that should be followed by cytology as a triage test in HPV-positive patients.

Materials and methods: We selected 40 cytological specimens of HPV-associated glandular lesions including atypical glandular cells, adenocarcinoma in situ (AIS), and adenocarcinoma. We confirmed their histological type using biopsy or excisional specimens. We examined the cytological features of the glandular lesions in detail.

Results: The majority of HPV-associated adenocarcinoma was usual-type adenocarcinoma with enlarged nuclei, increased nuclear density, and heterogeneous to pale nuclear chromatin and most cases showed apoptosis or mitosis. AIS exhibited stacked clusters with intense nuclear chromatin, so-called hyperchromatic crowded groups. AIS showed less nuclear pleomorphism compared to invasive adenocarcinoma and no background tumor diathesis. Conversely, adenocarcinoma tended to have a tumor diathesis. Stratified mucin-producing carcinoma had a foamy to vacuolated cytoplasm and tended to form nested clusters without a palisade arrangement. Some atypical glandular cells were found to have glandular involvement of high-grade squamous intraepithelial lesions by histology.

Conclusion: To contribute to the early detection of glandular lesions, it is important to recognize the fundamental cytological features, especially hyperchromatic crowded groups, background tumor diathesis, and nuclear findings.

Background: Fine-needle aspiration cytology (FNAC) is a minimally invasive and reliable technique for sampling lymph nodes, thymus, and spleen. However, morphological interpretation alone is often insufficient due to overlapping features among reactive, infectious, and neoplastic processes.

Objective: To review the essential role of ancillary testing in enhancing the diagnostic accuracy of FNAC in lymphoid and mediastinal organs.

Methods: A narrative review of the literature focusing on the applications, strengths, and limitations of flow cytometry, immunocytochemistry, in situ hybridization, and molecular testing in FNAC samples from lymph nodes, thymus, and spleen.

Results: Ancillary studies significantly increase the diagnostic precision of FNAC, enabling lineage assignment, clonality determination, detection of defining genetic alterations, and identification of therapeutic biomarkers. These techniques are particularly valuable in paucicellular aspirates, mediastinal lesions, splenic lymphomas, and cases with overlapping morphological patterns.

Conclusion: Integration of ancillary techniques with cytomorphology aligns FNAC with modern WHO and IAC-IARC-WHO diagnostic frameworks, transforming it into a powerful multiparametric tool that supports accurate diagnosis, subclassification, prognostication, and treatment planning.

Background: Cytological examination of a fine-needle aspirate (FNA) is a minimally invasive modality that is increasingly used in the diagnosis of lymphoma. Flow cytometry and other ancillary tests make an important contribution to the diagnostic value of FNAs of lymphoid lesions. This review follows the recent publication of the first edition of the WHO Reporting System for Lymph Node, Spleen, and Thymus Cytopathology. This WHO volume provides a framework for assessment of cytopathological samples and presents in detail the contribution of ancillary studies, including flow cytometry.

Summary: The current review is designed to complement the WHO volume. It presents criteria for adequacy of FNA specimens assessed by flow cytometry and includes strategies to determine the degree of blood contamination of FNA samples. Evidence for the contribution of flow cytometry to the diagnostic value of FNA is reviewed. The role of TRBC1 and TRBC2 in the assessment of T-cell populations is presented. Strengths of flow cytometry, along with its limitations, are presented.

Key messages: Provided these limitations are properly understood, the inclusion of flow cytometry as an ancillary modality makes a substantial contribution to FNA assessment.

Background: Cytologic examination of lymph nodes and serous effusions is of value in the diagnosis of small cell lymphomas. The World Health Organisation (WHO) has recently published a reporting system relating to the cytologic examination of lymph nodes, spleen, and thymus to standardise the approach to reporting such specimens.

Summary: An overview of the WHO reporting system is given with particular reference to the diagnosis of small B-cell lymphomas. The role of rapid on-site evaluation and ancillary testing is discussed. The cytomorphological features of specific small B-cell lymphomas and associated ancillary testing are described.

Key messages: The WHO reporting system provides a standardised approach to the reporting of cytological specimens from lymph nodes, the spleen, and the thymus. Small B-cell lymphomas pose a challenge to the cytopathologist due to their morphologic overlap with each other and reactive conditions. The importance of correlation and integration of cytomorphological appearances with clinical features and ancillary testing modalities to obtain a final diagnosis is emphasised. The present review includes a description of cytomorphological features according to pattern recognition and provides an overview of diagnostic criteria for specific entities based on cytomorphology alone and in combination with ancillary tests in different clinical settings discussing differential diagnoses and potential pitfalls.

Background: Cytotechnologists are integral members of the cytopathology team with their role extending beyond that of analyzing slides. They have a unique understanding of cytopreparation, laboratory systems, and workflows given their involvement in varied laboratory processes which makes them key players in quality control, quality assurance, and quality improvement measures. Many cytotechnologists endorse performing quality assurance and/or quality control activities as part of their duties.

Summary: In this article, we review some of the key quality control and assurance measures cytotechnologists are involved in with an emphasis on how they can take a leading role in systems operations and improvements.

Key messages: Cytotechnologists are essential to quality assurance and improvement in the cytopathology laboratory given their intimate knowledge and experience with cytopathology techniques and laboratory operations making them key contributors to maintaining and enhancing laboratory standards.

Background: Pap classes have been replaced by organ-specific reporting systems in recent decades; however, part of the cytological specimens is insufficient. The present review summarizes how different organ-specific systems define the insufficient category: both quantitative and qualitative criteria are used. In addition, the sample volume may be evaluated in certain specimens. Summary: The reasons for an insufficient sample may vary and depend either on the lesion itself or the sampling procedure. Key Messages: The management recommendations for insufficient specimens improve communication between cytopathologists and treating physicians.

Background: The advent of programmed cell death-1/programmed death-ligand 1 (PD-1/PD-L1) inhibitors has revolutionized lung cancer treatment, necessitating accurate PD-L1 immunohistochemical (IHC) assessment. While standardized for formalin-fixed paraffin-embedded histological samples, PD-L1 testing on cytology remains challenging. This review aims to address the complexities of PD-L1 IHC in cytology, focusing on validation guidelines, quality assessment, cytohistological correlation, and interobserver variability.

Summary: This review synthesizes current guidelines and research on PD-L1 IHC in cytology; in particular, recent College of American Pathologists (CAP) guidelines emphasize the necessity for rigorous validation, particularly for non-formalin-fixed specimens. As far as cytohistological concordance studies are concerned, the review of 48 original articles revealed significant variability in PD-L1 expression, with concordance rates ranging from 54 to 100% at the 1% cutoff and 82-100% at the 50% cutoff. Finally, interobserver variability, particularly in the 1-49% PD-L1 expression range, further complicates accurate assessment. The review also discusses the challenges associated with quality assessment in cytology, including the lack of standardized control materials and external quality assessment (EQA) programs specifically tailored for cytological samples.

Key messages: PD-L1 testing in cytology is feasible but faces substantial challenges compared to histological specimens. Validation of PD-L1 IHC protocols for cytological preparations, especially non-formalin-fixed samples, is essential. Concordance between cytological and histological PD-L1 expression is variable, highlighting the need for caution in interpretation. Interobserver variability, particularly in cases with intermediate PD-L1 expression (1-49%), affects diagnostic reproducibility. The development of standardized quality control materials and EQA programs for cytology is urgently needed to support consistent and reliable PD-L1 testing.

Background: Cervical cancer is the fourth most common cancer in women globally with highest incidence and mortality identified in less developed and medically underserved areas in the world. The diminishing cytology workforce, unavailability of expert consultation, and the high volume of Pap tests needing manual screening are the main reasons for exploring innovative solutions to help mitigate the negative effects resulting from the dearth of timely cervical cancer screening in certain population groups.

Summary: Developments in whole slide imaging and artificial intelligence (AI) have enabled the emergence of new computer-assisted systems that have the potential for transforming traditional cytopathology practice. However, AI-based systems are relatively new with limited published data on their validation and clinical utility in clinical practice. Our article aims to increase awareness of the availability of such systems, explores the history and development of AI-assisted screening platforms for Pap tests, compares the performance characteristics of various systems, elaborates on technical challenges associated with conducting clinical trials employing this technology, and discusses considerations around deploying such systems in routine cytopathology practice.

Key message: Revolutionary AI-based systems are being developed and utilized in cytopathology practice to screen Pap tests. Some of these systems have good performance characteristics and provide opportunities to combat various issues such as workload and standardization faced by cytology laboratories globally. However, judicious review of these systems using evidence-based studies is imperative to promote widespread adoption and maintain high-quality standards for patient safety.