Who Classification Of Tumours Of Haematopoietic And Lymphoid Tissues Pdf Download
The upcoming 5th edition of the World Health Organization (WHO) Classification of Haematolymphoid Tumours is part of an effort to hierarchically catalogue human cancers arising in various organ systems within a single relational database. This paper summarizes the new WHO classification scheme for myeloid and histiocytic/dendritic neoplasms and provides an overview of the principles and rationale underpinning changes from the prior edition. The definition and diagnosis of disease types continues to be based on multiple clinicopathologic parameters, but with refinement of diagnostic criteria and emphasis on therapeutically and/or prognostically actionable biomarkers. While a genetic basis for defining diseases is sought where possible, the classification strives to keep practical worldwide applicability in perspective. The result is an enhanced, contemporary, evidence-based classification of myeloid and histiocytic/dendritic neoplasms, rooted in molecular biology and an organizational structure that permits future scalability as new discoveries continue to inexorably inform future editions.
who classification of tumours of haematopoietic and lymphoid tissues pdf download
The aim of this paper is to provide an overview of the new edition of the WHO classification for myeloid and histiocytic/dendritic tumours. The last edition of the haematolymphoid classification dates back to 2008 and was revised in 2017. An overview of the lymphoid tumours is provided in a companion manuscript .
Mastocytosis comprises rare heterogeneous neoplasms characterized by an accumulation of abnormal mast cells in various organs or tissues, typically driven by constitutive activation of the KIT receptor. The pathology of mastocytosis is complex, and clinical features span a broad spectrum that may be modulated by the presence of comorbidities. Significant comorbidities include IgE-dependent allergies, vitamin D deficiency, and psychiatric, psychological or mental problems. The classification continues to recognize three disease types: systemic mastocytosis (SM), cutaneous mastocytosis (CM) and mast cell sarcoma (MCS) . (Table 2)
Myeloid sarcoma represents a unique tissue-based manifestation of AML or transformed MDS, MDS/MPN, or MPN. Cases of de novo myeloid sarcoma should be investigated comprehensively, including cytogenetic and molecular studies, for appropriate classification and planning therapy. Molecular alterations in myeloid sarcoma and concurrent bone marrow disease are concordant in 70% of patients, suggesting that myeloid sarcoma may be derived from a common haematopoietic stem cell or precursor [68, 69]. Relevant gene mutations are detected in a subset of patients with morphologically normal-appearing bone marrow, suggesting low-level clonal myeloid disease or CH in the bone marrow [68, 70].
Lymphoma is a malignancy of lymphocytes and lymphoid tissues comprising a heterogeneous group of diseases, with up to 80 entities now described. Lymphoma is the 6th most common cancer in Australia, affecting patients of all ages, with rising incidence rates. With the proliferation of efficacious novel agents, therapeutic strategies are increasingly diverse and survival is improving. There is a clear need for contemporary robust and detailed data on diagnostic, investigational and management strategies for this disease in Australia, New Zealand and worldwide, to inform and benchmark local and international standards of care. Clinical quality registries can provide these data, and support development of strategies to address variations in management, including serving as platforms for clinical trials and other research activities. The Lymphoma and Related Diseases Registry (LaRDR) was developed to capture details of patient demographics, disease characteristics, and management throughout their disease course and therapy and to develop outcome benchmarks nationally and internationally for lymphoma. This report describes the aims, development and implementation of the LaRDR, as well as challenges addressed in the process.
Lymphoid malignancies affect people of all ages, and impose a significant burden for patients and the health system, with high rates of hospitalisations for treatment delivery and for management of complications, such as infection . Therapies are often complex, and must be tailored to the specific type of lymphoid cancer with many patients undergoing multiple lines of therapy during the course of their disease; management may include a combination of chemotherapy, immunotherapy, small molecule drugs, radiation, cellular therapies such as autologous or allogeneic haematopoietic stem cell transplant or chimeric antigen-receptor T-cell therapeutics, and occasionally surgery, along with supportive care measures such as immunoglobulin replacement therapy and transfusions. Survival is improving likely due to improvements in diagnosis, better supportive care, and the availability of new targeted therapies, but many of these are costly, and also carry specific adverse effect profiles.
2. Swerdlow SH, Campo E, Harris NL, et al, eds. WHO classification of tumours of haematopoietic and lymphoid tissues. In: Bosman FT, Jaffe ES, Lakhani SR, Ohgaki H, eds. World Health Organization Classification of Tumours. Lyon, France: IARC; 2008.
Lymphomas are clonal neoplasms characterized by the expansion of abnormal lymphoid cells that may develop in any organ but commonly involve lymph nodes. The fourth edition of the World Health Organization (WHO) Classification of Tumours of Haematopoietic and Lymphoid tissues, published in 2008, is the official and most current guideline used for diagnosis of lymphoid neoplasms.2 The WHO scheme classifies lymphomas according to the type of cell from which they are derived (mature and immature B cells, T cells, or natural killer (NK) cells, findings determined by their morphology and immunophenotype) and their clinical, cytogenetic, and/or molecular features. This official classification is currently being updated3 and is expected to be published in full in 2017, at which time it is anticipated to include definitions for more than 70 distinct neoplasms.
Both reactive and neoplastic processes have variably unique morphologic features that if properly recognized, guide the subsequent testing. However, some reactive and neoplastic processes can present with overlapping features, and even after extensive immunophenotypic evaluation and the performance of ancillary studies, it may not be possible to conclusively determine its nature. If the lymph node architecture is altered or effaced, the predominant pattern of infiltration (eg, nodular, diffuse, interfollicular, intrasinusoidal) and the degree of alteration of the normal architecture is evaluated, usually at low magnification. When the presence of an infiltrate is recognized, its components must be characterized. If the infiltrate is composed of a homogeneous expansion of lymphoid cells that disrupts or replaces the normal lymphoid architecture, a lymphoma will be suspected or diagnosed. The pattern of distribution of the cells along with their individual morphologic characteristics (ie, size, nuclear shape, chromatin configuration, nucleoli, amount and hue of cytoplasm) are key factors for the diagnosis and classification of the lymphoma that will guide subsequent testing. The immunophenotypic analysis (by immunohistochemistry, flow cytometry or a combination of both) may confirm the reactive or neoplastic nature of the process, and its subclassification. B-cell lymphomas, in particular have variable and distinctive histologic features: as a diffuse infiltrate of large mature lymphoid cells (eg, diffuse large B-cell lymphoma), an expansion of immature lymphoid cells (lymphoblastic lymphoma), and a nodular infiltrate of small, intermediate and/or mature large B cells (eg, follicular lymphoma).
1. Siegel RL, Miller KD, Jemal A. Cancer Statistics, 2017. CA Cancer J Clin. 2017 ;67(1):7-30.2. Swerdlow SH, Campo E, Harris NL, et al, eds. WHO classification of tumours of haematopoietic and lymphoid tissues. In: Bosman FT, Jaffe ES, Lakhani SR, Ohgaki H, eds. World Health Organization Classification of Tumours. Lyon, France: IARC; 2008.3. Swerdlow SH, Campo E, Pileri SA, et al. The 2016 revision of the World Health Organization classification of lymphoid neoplasms. Blood. 2016 ;127(20):2375-2390.
Bladder tumours: In line with recommendations of the European Network of Cancer Registries (ENCR) and subsequently the UK Association of Cancer Registries (UKACR), the SCR began coding non-invasive bladder carcinomas as neoplasms of uncertain behaviour or in situ carcinomas (depending on tumour grade). Prior to this, and in accordance with the index of the tenth revision of the International Classification of Diseases (ICD-10), the term 'bladder carcinoma' was coded as invasive disease (ICD-10 C67) unless otherwise specified. The change occurred around the year 2000. It led to an apparent decrease in the incidence of invasive bladder cancer, and a corresponding decrease in survival (due to the reclassification of better prognosis tumours as uncertain or in situ ). For this reason, bladder tumours of all behaviours are combined for the purposes of some analyses, especially for analysis of secular trends.
We herein present an overview of the upcoming 5th edition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4th edition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5th edition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms.