The World Health Organization Classification of Hematological Malignancies Report of the Clinical Advisory Committee Meeting, Airlie House, Virginia, November 1997

Abstract

The Society for Hematopathology and the European Association of Hematopathologists have undertaken as a joint project the development of a classification of hematologic neoplasms for the World Health Organization (WHO). A steering committee composed of members of both societies has been formed, and 10 committees have been assigned the task of arriving at a consensus list of myeloid, lymphoid, and histiocytic neoplasms, with descriptions and criteria for diagnosis. A new classification for lymphoid neoplasms was recently proposed (1), and the goals of the WHO project are to update and revise that classification, with input from additional experts to broaden the consensus, and to extend the principles of disease definition and consensus building to the myeloid and histiocytic neoplasms. More than 50 pathologists from around the world have been involved in the project since 1995. Proponents of all major lymphoma and leukemia classifications have agreed that if a reasonable consensus emerges from this effort, they will accept the WHO as the standard classification of hematologic malignancies.The proposed WHO classification of hematologic malignancies stratifies these neoplasms primarily according to lineage: myeloid neoplasms, lymphoid neoplasms, mast cell disorders, and histiocytic neoplasms (Tables 1-5). Within each category, distinct diseases are defined according to a combination of morphology, immunophenotype, genetic features, and clinical syndromes. The relative importance of each of these criteria differs among the neoplasms, and there is no one gold standard for classification of all hematologic malignancies. The goal is to define disease entities that can be recognized by pathologists and that have clinical relevance.To ensure that the proposed classification will be of maximum use to oncologists, the Steering Committee invited expert hematologists and oncologists to form a Clinical Advisory Committee (CAC), with American and European co-chairs. The charge to the committee was to review the proposed classification and advise the pathologists on its clinical utility. More than 40 hematologists and oncologists from around the world agreed to participate. The proposed classification was circulated, and all participants were invited to submit topics and questions for discussion. A meeting was held in November 1997 at Airlie House, Virginia, to which the CAC and all pathologists involved in the WHO committees, as well as the Executive Committees of the two hematopathology societies, were invited.The meeting was organized around a series of questions, developed from those submitted by CAC members as well as those posed by the pathologists. Only issues that were controversial were discussed; diseases for which there were no new questions or data were accepted as previously defined. Only lymphoid and myeloid neoplasms were discussed at this meeting; histiocytic and mast cell tumors were not considered. Participants were invited to present data relevant to each question, and open discussion followed. At the end of ...

PKC-beta II expression has prognostic impact in nodal diffuse large B-cell lymphoma

“…Diagnoses were confirmed by histopathologic review, using morphologic and immunologic criteria defined in the WHO classification. 10 All cases were CD20 positive.…”

Primary Bilateral Adrenal Intravascular Large B-cell Lymphoma Associated with Adrenal Failure

“…The final diagnosis was IVL based on histopathological examination. IVL was classified as diffuse large B-cell lymphomasubtype, according to the new WHO classification (8). Several cases of IVL have been reported since the first patient was reported by Pfleger and Tappeiner (9).…”

Phase 2 study of intrathecal, long‐acting liposomal cytarabine in the prophylaxis of lymphomatous meningitis in human immunodeficiency virus‐related non‐Hodgkin lymphoma

“…Patients were enrolled into the study if they met the following inclusion criteria: biopsy-proven NHL according to World Health Organization (WHO) classification, 32 age >18 years, confirmed HIV infection, no previous chemotherapy for lymphoma, and absence of lymphomatous cells by cytology in CSF. All patients signed informed consent before entry into the study.…”