The WHO classification has produced a new and exciting degree of cooperation and communication between oncologists and pathologists from around the world, which should facilitate progress in the understanding and treatment of hematologic malignancies.

Clinical analysis of our cohort leads us to define NBO as a distinct disease entity with three clinical presentations: acute NBO, chronic recurrent multifocal osteomyelitis or persistent chronic NBO. Diagnostic criteria were proposed to differentiate NBO from diseases with similar clinical presentation.

The experience of developing the WHO Classification has produced a new and exciting degree of cooperation and communication between oncologists and pathologists from around the world, which should facilitate progress in the understanding and treatment of hematologic malignancies.

No abstract

No abstract

The experience of developing the WHO classification has produced a new and exciting degree of cooperation and communication between oncologists and pathologists from around the world, which should facilitate progress in the understanding and treatment of haematological malignancies.

Background: Peripheral T-cell lymphoma (PTCL) is rare in most parts of the world. Therefore, we have evaluated the 96 cases of PTCL diagnosed within the Non-Hodgkin's Lymphoma Classification Project (NHLCP) (1378 cases) for their geographical distribution, pathologic features and diagnostic reliability, as well as clinical presentation and outcome. Materials and methods:Diagnoses of all cases were rendered independently by five experienced hematopathologists based on morphology only, and after introduction of the immunophenotype and clinical data. Divergent diagnoses were jointly discussed and a final consensus diagnosis was established in each case. Reliability of the diagnoses was evaluated statistically, and the clinical features and outcome were analyzed according to the consensus diagnoses.Results: Seven per cent of all non-Hodgkin's lymphoma (NHL) cases reviewed were classified as PTCL and the frequency varied from 1.5% to 18.3% in different countries. The interobserver agreement with the consensus diagnosis of PTCL was 86% in the Revised European-American Lymphoma (REAL) classification, but the designation of subtypes was less reliable. Diagnostic reliability improved from 41% to 86% after immunophenotyping, but did not improve further with the addition of detailed clinical data. Clinically, angiocentric nasal lymphoma presented in young females (median age 49 years) at extranodal sites, but with few adverse risk factors, whereas angioimmunoblastic lymphoma presented most often in older males (median age 65 years) at nodal and extranodal sites with numerous risk factors. The 5-year overall and failure-free survivals for patients with PTCL treated with doxorubicin (Adriamycin)-containing regimens were only 26% and 20%, respectively. Both failure-free and overall survival were strongly correlated with the performance status and International Prognostic Index scores at presentation, but differences in survival were not observed between the major histological types. However, within the PTCL 'not otherwise specified' category, but not angioimmunoblastic lymphoma, the number of transformed blasts was prognostically relevant. Conclusions:PTCLs can be diagnosed reliably by experienced hematopathologists, but immunophenotyping is absolutely necessary. Currently, all types of PTCL should be considered high-grade lymphomas. An increased ability to distinguish T-lymphocyte subsets is needed in order to better subclassify the PTCLs for therapeutic and prognostic purposes.

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 ...