Harvey R. Gralnick

Proposals for the Classification of the Acute Leukaemias French-American-British (FAB) Co-operative Group

Summary. A uniform system of classification and nomenclature of the acute leukaemias, at present lacking, should permit more accurate recording of the distribution of cases entered into clinical trials, and could provide a reference standard when newly developed cell‐surface markers believed to characterize specific cell types are applied to cases of acute leukaemia. Proposals based on conventional morphological and cytochemical methods are offered following the study of peripheral blood and bone‐marrow films from some 200 cases of acute leukaemia by a group of seven French, American and British haematologists. The slides were examined first independently, and then by the group working together. Two groups of acute leukaemia,‘lymphoblastic’and myeloid are further subdivided into three and six groups. Dysmyelopoietic syndromes that may be confused with acute myeloid leukaemia are also considered. Photomicrographs of each of the named conditions are presented.

Proposals for the classification of the myelodysplastic syndromes

Summary. 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 one 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.

Proposed Revised Criteria for the Classification of Acute Myeloid Leukemia: A Report of the French-American-British Cooperative Group

Excerpt The first proposals for the morphologic classification of the acute leukemias by the French-American-British (FAB) group (1) were put forward in the hope that they might serve as a basis fo...

NIH CONFERENCE. THE IDIOPATHIC HYPEREOSINOPHILIC SYNDROME. CLINICAL, PATHOPHYSIOLOGIC, AND THERAPEUTIC CONSIDERATIONS

Abstract The idiopathic hypereosinophilic syndrome (HES) represents a heterogeneous group of disorders with the common features of prolonged eosinophilia of an undetectable cause and organ system d...The idiopathic hypereosinophilic syndrome (HES) represents a heterogeneous group of disorders with the common features of prolonged eosinophilia of an undetectable cause and organ system dysfunction. Fifty patients with the idiopathic HES were studied over 11 years of the National Institutes of Health. Multiple organ systems were involved; bone marrow hypereosinophilia was common to all patients, but the most severe clinicopathologic involvement was of the heart and nervous system. Postmortem gross pathologic examination of the hearts of patients with idiopathic and nonidiopathic HES suggested that the common mechanism of cardiac disease is the eosinophilia. Endomyocardial biopsy findings showed that the endothelial cells in the endocardium and of the microvasculature were the primary targets of the tissue damage. This damage initiates thrombosis; endocardial fibrosis and restrictive endomyocardopathy may follow. In-vitro culture of circulating eosinophil colony-forming units showed some normal studies, some studies showing increased progenitor cells committed to eosinophil development, and others showing an excess production of eosinophil colony-stimulating factor. Chemotherapy to lower the eosinophil counts has resulted in marked improvement of HES prognosis, as have agressive medical and surgical approaches to cardiovascular complications.

Criteria for the Diagnosis of Acute Leukemia of Megakaryocyte Lineage (M7): A Report of the French-American-British Cooperative Group

For the diagnosis of M7, the bone marrow aspirate shows a leukemic cell infiltrate that comprises 30% or more of all cells. These cells are identified as being of megakaryocyte lineage by the platelet peroxidase reaction on electron microscopy or by tests with monoclonal or polyclonal platelet-specific antibodies. Myelofibrosis or increased bone marrow reticulin are a prominent aspect in most patients with M7. In patients with increased reticulin, the bone marrow sample may be difficult to obtain and the counts done on the marrow films may be misleading. In these patients, the diagnosis of M7 should be based on excellent bone marrow biopsy sections that show an excess of blasts and, at times, increased numbers of maturing megakaryocytes; and on the presence of unequivocal megakaryoblasts in the peripheral blood or bone marrow (or both) as shown by immunologic techniques.

Proposals for the classification of chronic (mature) B and T lymphoid leukaemias. French-American-British (FAB) Cooperative Group.

Peripheral blood, bone marrow films, and bone marrow biopsy specimens from 110 patients, well characterised by clinical and laboratory studies, including electron microscopy, were reviewed, to determine proposals for the classification of chronic (mature) B and T cell leukaemias. On the basis of cytology and membrane phenotype the following disorders were defined: (i) B cell type: chronic lymphocytic leukaemia (CLL); CLL of mixed cell type, which includes cases with more than 10% and less than 55% prolymphocytes (CLL/PL), and a less well defined form with pleomorphic lymphocytes but less than 10% prolymphocytes; prolymphocytic leukaemia (PLL); hairy cell leukaemia (HCL); HCL variant; splenic lymphoma with circulating villous lymphocytes; leukaemic phase of non-Hodgkins lymphoma (follicular lymphoma, intermediate, or mantle zone lymphoma and others); lymphoplasmacytic lymphoma with peripheral blood disease (mostly Waldenströms macroglobulinaemia); and plasma cell leukaemia. (ii) T cell type: T/CLL, which was differentiated from reactive T/lymphocytosis; T/PLL; adult T cell leukaemia/lymphoma; and Sézarys syndrome. The recognition of distinct entities within the B and T cell leukaemias seems to have clinical and epidemiological connotations. It is hoped that these proposals may serve as the basis for further work, discussion, and improved management of patients.

The Morphological Classification of Acute Lymphoblastic Leukaemia: Concordance among Observers and Clinical Correlations

Summary. The degree of concordance in the morphological classification of ALL was assessed by the FAB group after two successive reviews of 200 and 100 slides respectively. As a result, a simple scoring system for types L1 and L2 is proposed based on the following four features: (1) nuclear cytoplasmic ratio, (2) presence, prominence and frequency of nucleoli, (3) regularity of nuclear membrane outline, and (4) cell size. By this method, the overall concordance by seven observers (agreement of 7:0 or 6:1 only) increased from 63% to 84%.

The chronic myeloid leukaemias: guidelines for distinguishing chronic granulocytic, atypical chronic myeloid, and chronic myelomonocytic leukaemia. Proposals by the French-American-British Cooperative Leukaemia Group.

Summary. We have reviewed our experience with four of the entities that are included under the generic term chronic myeloid leukaemia (CML), namely the classic Ph+ CGL, both BCR+ and BCR−, aCML and CMML. We have developed a statstical model that confirms that CGL, aCML and CMML can be distinguished from each other with reasonable success employing five quantitative parameters (WBC, percentage immature granulocytes, percentage monocytes, percentage basophils, percentage erythroid precursors in bone marrow) and one qualitative parameter (granulocytic dysplasia). It is hoped that these detailed recommendations will enable investigators to improve their diagnostic accuracy. This should permit more uniform comparisons of molecular biologic and clinical studies.

American Burkitt's lymphoma: a clinicopathologic study of 30 cases. I. Clinical factors relating to prolonged survival.

The presenting clinical characteristics and the results of therapy in 30 cases of American Burkitts lymphoma are described. Five patients presented with localized disease. The abdomen was the most frequent site of involvement (19 cases). Serum lactic dehydrogenase (LDH) levels closely correlated with extent of tumor mass. Of the 22 patients treated with large doses of parenteral cyclophosphamide, complete remission was achieved in 13 (59 per cent). Of these only four have had a relapse, all within 12 months of treatment. The remainder are alive, free of disease and have not received any treatment for up to 80 months or more. The site and volume of tumor mass predicted for prolonged survival. None of the six patients with bone marrow or central nervous system involvement remained tumor-free. A complete remission was achieved in 8 of 9 patients with presenting LDH levels of less than 700 IU/ml and they have remained free of disease, whereas only 4 of 13 patients with LDH levels greater than 700 IU/ml had a complete response and 3 of these had a relapse within 12 months. In six cases, the massive tumor regression following chemotherapy was associated with serious metabolid consequences including hyperkalemia (six cases), hypocalcemia, hyperphosphatemia (one case) and lactic acidosis (one case). There were four sudden deaths in less than 48 hours after chemotherapy; two of these were attributable to hyperkalemia. In all cases therw were large tumor masses and/or elevated serum LDH levels.

Classification of Acute Leukemia

Abstract The classification of acute leukemia has almost invariably been based on the morphologic diagnosis into two broad categories: acute lymphocytic and acute myeloid leukemia. Despite the wide...