Search

* Context.--This article is based on a talk given by the lead author at the Eigth Annual Princeton Integrated Pathology Symposium: Breast Pathology, on Sunday, April 11, 2021. Objective.--To show how the World Health Organization (WHO) Classification of Tumours links to the requirements for quality assurance in breast pathology, including both immunohistochemistry and molecular pathology. Data Sources.--The WHO Classification of Tumours 5th edition Breast Tumours entries formed the basis of the talk, together with guidance published by the International Quality Network for Pathology. Conclusions.--The WHO Classification of Tumours provides a definitive set of international standards for tumor diagnosis contributed by experts, based on available clinical and research evidence. Techniques used in pathology need internal and external quality assurance to ensure accurate reports for patient management. doi: 10.5858/arpa.2021-0491-RA, The World Health Organization (WHO) Classification of Tumours now has 5 volumes published in the 5th edition, and will eventually encompass all tumors within a single classification (https://whobluebooks.iarc.who.int). The volume [...]

Aims: Ductal carcinoma in situ (DCIS) is recognised by the World Health Organisation (WHO) Classification of Tumours (WCT) as a non‐invasive neoplastic epithelial proliferation confined to the mammary ducts and lobules. This report categorises the references cited in the DCIS chapter of the 5th edition of the WCT (Breast Tumours) according to prevailing evidence levels for evidence‐based medicine and the Hierarchy of Evidence for Tumour Pathology (HETP), identifying potential gaps that can inform subsequent editions of the WCT for this tumour. Methods and results: We included all citations from the DCIS chapter of the WCT (Breast Tumours, 5th edition). Each citation was appraised according to its study design and evidence level. We developed our map of cited evidence, which is a graphical matrix of tumour type (column) and tumour descriptors (rows). Spheres were used to represent the evidence, with size and colour corresponding to their number and evidence level respectively. Thirty‐six publications were retrieved. The cited literature in the DCIS chapter comprised mainly case series and were regarded as low‐level. We found an unequal distribution of citations among tumour descriptors. 'Pathogenesis' and 'prognosis and prediction' contained the most references, while 'clinical features', 'aetiology' and 'diagnostic molecular pathology' had only a single citation each. 'Prognosis and prediction' had the greatest proportion of moderate‐ and high‐levels of evidence. Conclusion: Our findings align with the disposition for observational studies inherent in the field of pathology. Our map is a springboard for future efforts in mapping all available evidence on DCIS, potentially augmenting the editorial process and future editions of WCTs. [ABSTRACT FROM AUTHOR]

* Context.--There have been major advances in the understanding of melanoma since the last revision of the World Health Organization (WHO) classification in 2006. Objective.--To discuss development of the 9 distinct types of melanoma and distinguishing them by their epidemiology, clinical and histologic morphology, and genomic characteristics. Each melanoma subtype is placed at the end of an evolutionary pathway that is rooted in its respective precursor, wherever appropriate and feasible, based on currently known data. Each precursor has a variable risk of progression culminating in its fully evolved, invasive melanoma. Data Sources.--This review is based on the 'Melanocytic Tumours' section of the 4th edition of the WHO Classification of Skin Tumours, published in 2018. Conclusions.--Melanomas were divided into those etiologically related to sun exposure and those that are not, as determined by their mutational signatures, anatomic site, and epidemiology. Melanomas on the sun-exposed skin were further divided by the histopathologic degree of cumulative solar damage (CSD) of the surrounding skin, into low and high CSD, on the basis of degree of associated solar elastosis. Low-CSD melanomas include superficial spreading melanomas and high-CSD melanomas incorporate lentigo maligna and desmoplastic melanomas. The 'nonsolar' category includes acral melanomas, some melanomas in congenital nevi, melanomas in blue nevi, Spitz melanomas, mucosal melanomas, and uveal melanomas. The general term melanocytoma is proposed to encompass 'intermediate' tumors that have an increased (though still low) probability of disease progression to melanoma. (Arch Pathol Lab Med. 2020;144:500-522; doi: 10.5858/arpa.2019-0561-RA), This monograph represents a summary and discussion of a classification of melanoma that was developed for the WHO Classification of Skin Tumours, 4th edition, published in 2018. (1) As in [...]

The recently published WHO Reporting System for Pancreaticobiliary Cytopathology (World Health Organization [WHO] System) is an international approach to the standardized reporting of pancreaticobiliary cytopathology, updating the Papanicolaou Society of Cytopathology System for Reporting Pancreaticobiliary Cytology (PSC System). Significant changes were made to the categorization of benign neoplasms, intraductal neoplasms, mucinous cystic neoplasms, and malignant neoplasms considered low grade. Benign neoplasms, such as serous cystadenoma, categorized as Neoplastic: benign in the PSC system, are categorized as Benign/negative for malignancy in the WHO system. Pancreatic neuroendocrine tumor, solid‐pseudopapillary neoplasm, and gastrointestinal stromal tumor, categorized as Neoplastic: other in the PSC system, are categorized as Malignant in the WHO System in accord with their classification in the 5th edition WHO Classification of Digestive System Tumours (2019). The two new categories of Pancreaticobiliary Neoplasm Low‐risk/grade and Pancreaticobiliary Neoplasm High‐risk/grade are mostly limited to intraductal neoplasms and mucinous cystic neoplasms. Low‐risk/grade lesions are mucinous cysts, with or without low‐grade epithelial atypia. High‐risk/grade lesions contain neoplastic epithelium with high‐grade epithelial atypia. Correlation with clinical, imaging, and ancillary studies remains a key tenet. The sections for each entity are written to highlight key cytopathological features and cytopathological differential diagnoses with the pathologist working in low resource setting in mind. Each section also includes the most pertinent ancillary studies useful for the differential diagnosis. Sample reports are provided for each category. Finally, the book provides a separate section with risk of malignancy and management recommendations for each category to facilitate decision‐making for clinicians. The recently published World Health Organization System for reporting pancreatobiliary cytopathology is an update to the Papanicolaou System for reporting pancreatobiliary cytopathology, building on the key concepts and changing the categorization of some neoplasms to better reflect their biological behavior. This review summarizes the key points and organization. [ABSTRACT FROM AUTHOR]

The International Academy of Cytology has joined with the International Agency for Research on Cancer and the World Health Organization (WHO) to develop international systems for reporting the cytopathology of lung, pancreas and biliary tract, lymph nodes, soft tissue, liver, breast, and kidney and adrenal gland. The WHO recently published the reporting systems for lung and pancreaticobiliary cytopathology. The objectives of this collaboration are to standardize the reporting of cytopathology; improve the quality of reporting by establishing the key diagnostic cytopathological features of entities and neoplasms; provide detailed best‐practice guidelines in sampling techniques, specimen handling and processing, and the use of ancillary techniques; and facilitate communication between cytopathologists and clinicians to improve patient care. Each WHO system has defined specific categories and terminology for reporting cytopathology, and each category has an estimated risk of malignancy as far as the current literature allows and a suggested diagnostic management algorithm to assist clinicians. The WHO systems recognize that local medical and pathology infrastructure will vary, particularly in low‐income and middle‐income countries, and the WHO systems and their diagnostic management recommendations have been developed to allow them to be applied worldwide in all resource settings. The process of the selection of editors and authors and the writing and editing responsibilities has used the same model as that used for the fifth edition WHO Classification of Tumours, to which the WHO cytopathology systems are directly linked. This review provides the rationale and history of this joint International Academy of Cytology, International Agency for Research on Cancer, and WHO cytopathology project and a brief overview of the WHO reporting systems for lung and pancreaticobiliary cytopathology. The World Health Organization (WHO) reporting systems for lung and pancreaticobiliary cytopathology were recently published and will be closely followed by the publication of WHO reporting systems for lymph node, spleen and thymus, and soft tissue cytopathology and then reporting systems on liver, breast, and kidney and adrenal. This review provides the rationale and history of this joint International Academy of Cytology, International Agency for Research on Cancer, and WHO cytopathology project and a brief overview of the WHO reporting systems for lung and pancreaticobiliary cytopathology. [ABSTRACT FROM AUTHOR]

• The first editions of the World Health Organization (WHO) Reporting System for Lung and Pancreaticobiliary Cytopathology have recently been published. • This is a joint project of the International Academy of Cytology and the International Agency for Research on Cancer, part of WHO. • These systems link to the WHO Classification of Tumors and provide a cytological perspective. • Standardized reporting is encouraged and examples given in the volumes. • The reporting systems are intended to raise the profile and promote the use of cytopathology. [ABSTRACT FROM AUTHOR]

Aims: Breast phyllodes tumours (PTs) are a rare subset of fibroepithelial neoplasms categorised into benign, borderline, and malignant grades according to the World Health Organization (WHO) Classification of Tumours (WCTs). In this report, we developed an evidence gap map (EGM) based on the literature cited in the PT chapter of the 5th edition of the breast WCT in order to identify knowledge and research gaps in PT. Methods: A framework was first established where the dimensions of the EGM were defined as categories of tumour descriptors, tumour types, and evidence levels. Citations were collected into a Microsoft Excel form and imported into EPPI‐reviewer to produce the EGM. Results: The EGM showed that the "Histopathology" and "Pathogenesis" sections contained the most citations, the majority being of low‐level evidence. The highest number of citations considered of moderate‐level evidence were found in the "Histopathology" section. There was no high‐level evidence cited in this chapter. The "Localisation", "Aetiology", and "Staging" sections had the fewest citations. Conclusion: This EGM provides a visual representation of the cited literature in the PT chapter of the breast WCT, revealing the lack of high‐level evidence citations. There is an uneven distribution of references, probably due to citation practices. Pockets of low‐level evidence are highlighted, possibly related to referencing habits, lack of relevant research, or the belief that the information presented is standard accepted fact, without the need for specific citations. Future work needs to bridge evidence gaps and broaden citations beyond those in the latest WCT. [ABSTRACT FROM AUTHOR]

Laboratory medicine has reached the era where promises of artificial intelligence and machine learning (AI/ML) seem palpable. Currently, the primary responsibility for risk-benefit assessment in clinical practice resides with the medical director. Unfortunately, there is no tool or concept that enables diagnostic quality assessment for the various potential AI/ML applications. Specifically, we noted that an operational definition of laboratory diagnostic quality – for the specific purpose of assessing AI/ML improvements – is currently missing. A session at the 3rd Strategic Conference of the European Federation of Laboratory Medicine in 2022 on "AI in the Laboratory of the Future" prompted an expert roundtable discussion. Here we present a conceptual diagnostic quality framework for the specific purpose of assessing AI/ML implementations. The presented framework is termed diagnostic quality model (DQM) and distinguishes AI/ML improvements at the test, procedure, laboratory, or healthcare ecosystem level. The operational definition illustrates the nested relationship among these levels. The model can help to define relevant objectives for implementation and how levels come together to form coherent diagnostics. The affected levels are referred to as scope and we provide a rubric to quantify AI/ML improvements while complying with existing, mandated regulatory standards. We present 4 relevant clinical scenarios including multi-modal diagnostics and compare the model to existing quality management systems. A diagnostic quality model is essential to navigate the complexities of clinical AI/ML implementations. The presented diagnostic quality framework can help to specify and communicate the key implications of AI/ML solutions in laboratory diagnostics. [ABSTRACT FROM AUTHOR]