WHO CLASSIFICATION OF TUMOURS OF HAEMATOPOIETIC AND LYMPHOID TISSUES , WHO CLASSIFICATION OF TUMOURS OF HAEMATOPOIETIC AND LYMPHOID TISSUES , کتابخانه مرکزی دانشگاه علوم پزشکی تهران

WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues

The 2016 revision of the World Health Organization classification of lymphoid neoplasms

https://redbook.streamliners.co.nz/MPD_WHO-classification_vardiman_blood2009.pdf

The 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia: rationale and important changes

In HLH-94, the first prospective international treatment study for hemophagocytic lymphohistiocytosis (HLH), diagnosis was based on five criteria (fever, splenomegaly, bicytopenia, hypertriglyceridemia and/or hypofibrinogenemia, and hemophagocytosis). In HLH-2004 three additional criteria are introduced; low/absent NK-cell-activity, hyperferritinemia, and high-soluble interleukin-2-receptor levels. Altogether five of these eight criteria must be fulfilled, unless family history or molecular diagnosis is consistent with HLH. HLH-2004 chemo-immunotherapy includes etoposide, dexamethasone, cyclosporine A upfront and, in selected patients, intrathecal therapy with methotrexate and corticosteroids. Subsequent hematopoietic stem cell transplantation (HSCT) is recommended for patients with familial disease or molecular diagnosis, and patients with severe and persistent, or reactivated, disease. In order to hopefully further improve diagnosis, therapy and biological understanding, participation in HLH studies is encouraged.

HLH-2004: Diagnostic and therapeutic guidelines for hemophagocytic lymphohistiocytosis.

New diagnostic criteria for the diagnosis of the various myelodysplastic syndromes (MDS) are proposed, and a detailed description is given of the features that may help define MDS. Five MDS are described: (1) refractory anaemia (RA), (2) RA with ring sideroblasts, (3) RA with excess of blasts (RAEB), (4) chronic myelomonocytic leukaemia (CMML), and (5) RAEB 'in transformation'. One of the main distinguishing features of these conditions is the proportion of blast cells in the peripheral blood (PB) and/or bone marrow (BM). The morphological features of the blast cells that are of diagnostic importance have been redefined. In RA, with or without ringed sideroblasts, there are fewer than 1% of blasts in the PB and fewer than 5% in the BM; RAEB is defined as having between 5% and 20% of blasts in the BM and fewer than 5% in the PB; RAEB in transformation (a newly defined category) will be considered when any of the following features is present: (i) more than 5% of blasts in the PB, (ii) 20-30% in the BM, and (iii) the presence of Auer rods in granulocyte precursors in BM or PB. In accordance with these newly defined criteria, it is now proposed that over 30% of bone marrow blasts will suffice for the diagnosis of acute myeloid leukaemia (AML) in any of its forms (M1-M6). The proposed descriptions of the MDS should facilitate the interpretation of data emerging from cytogenetic and bone marrow culture studies and the search for features of possible prognostic significance. Recognition of the new category, RAEB in transformation, may throw light on the pathogenesis of AML.

Proposals for the classification of the myelodysplastic syndromes.

Nineteen patients whose bone marrow smears showed histiocytic hyperplasia with prominent hemophagocytosis were found to have a clinicopathologic syndrome associated with active viral infection. High fever, constitutional symptoms, liver function, and coagulation abnormalities and peripheral blood cytopenias were characteristic findings. Hepatosplenomegaly, lymphadenopathy, bilateral pulmonary infiltrates, and skin rash were often present. Fourteen of the patients were immunosuppressed. Active infection by herpes group viruses was documented in 14 patients and by adenovirus in 1. The bone marrow of most patients also showed decreased granulopoiesis and erythropoiesis with normal to increased numbers of megakaryocytes. Treatment generally consisted of supportive therapy and withdrawal of immunosuppressive drugs. Thirteen patients recovered. Lymph node biopsy and autopsy material showed generalized histiocytic hyperplasia with hemophagocytosis. The relationship of this disorder to familial hemophagocytic reticulosis, familial erythrophagocytic lymphohistiocytosis, histiocytic medullary reticulosis, and malignant histiocytosis is discussed. Immunosuppressive and cytotoxic therapy may be contraindicated in the treatment of this virus-associated syndrome.

Virus-associated hemophagocytic syndrome: a benign histiocytic proliferation distinct from malignant histiocytosis.

The lymphoproliferative processes that developed in five renal transplant recipients were studied in an attempt to characterize and classify them morphologically. Nine surgical specimens, hematological material on all patients, and autopsy specimens from three patients were available. Studies performed included: conventional histopathology; evaluation of cell markers (immunoglobulins and sheep erythrocyte, complement, and Fc receptors) and cytoplasmic immunoglobulins (peroxidase-antiperoxidase technique); ultrastructural examination; and karyotype analysis. The lymphoid lesions in our patients shared marked cytological polymorphism (small and large cells, of both follicular center and “medullary” type) and polyclonal B-cell features, which indicated a common reactive nonneoplastic origin. However, other features, such as morphological atypia of the immunoblasts, extensive necrosis, chromosomal aberrations, and an incipient monoclonal component suggested the development of lymphoma in some of these lesions. In contradistinction, the abundance of typical immunoblasts was a feature that seemed to correlate with the clinical activity of the disease rather than with the biological malignancy. The multiplicity of B-cell types and the presence of a follicular center cell component with diffuse distribution, as well as the extensive necrosis in the malignant forms, seem to differentiate morphologically the lymphoproliferative processes arising in transplant recipients from both the hyperplasias and the lymphomas developing in immunologically normal hosts. For the former, we propose the terms of “polymorphic diffuse B-cell hyperplasias” and “polymorphic B-cell lymphomas.”

https://cancerres.aacrjournals.org/content/canres/41/11_Part_1/4262.full.pdf

Robert W. McKenna

Papers

Virus-associated hemophagocytic syndrome: a benign histiocytic proliferation distinct from malignant histiocytosis.

Polymorphic diffuse B-cell hyperplasias and lymphomas in renal transplant recipients.

Immunophenotypic analysis of hematogones (B-lymphocyte precursors) in 662 consecutive bone marrow specimens by 4-color flow cytometry.

Therapy-related acute myeloid leukemia and myelodysplastic syndrome: a clinical and morphologic study of 65 cases.

Virus associated hemophagocytic syndrome