Bone marrow features improve prognostic efficiency in multivariate risk classification of chronic-phase Ph(1+) chronic myelogenous leukemia: a multicenter trial.

PURPOSE: Multivariate risk classifications for chronic (stable)-phase Ph(1+) chronic myelogenous leukemia (CML) are generally focused on hematologic variables, and the putative prognostic property of bone morphology has been neglected or even contested so far. PATIENTS AND METHODS: A total of 510 consecutively recruited patients in first chronic phase Ph(1+) CML and pretreatment bone marrow biopsy specimens were entered onto this multicenter observational trial to evaluate the effect of bone marrow histopathology. According to generally accepted criteria, patients with any signs of accelerated disease were excluded. Treatment modalities included administration of interferon alfa-2b (IFN) and chemotherapy with hydroxyurea (HU) or busulfan. Immunohistochemical and morphometric techniques were applied to identify marrow cells and to quantify fiber density. Patients were separated into learning and validation samples, and classification and regression tree (CART) analysis was performed to establish a prognostic decision tree. RESULTS: CART analysis of the validation sample (123 patients with HU therapy) revealed the amount of erythroid precursors in the bone marrow, myelofibrosis, and splenomegaly as the most important prognostic features. Three risk profiles with significantly different survival patterns were established, with median survival times ranging from 33 to 108 months (two-sided log-rank test, P =.0001). The new score was confirmed by application to the learning sample with IFN therapy (two-sided log-rank test, P =.0002). Furthermore, risk status defined by the new score was significantly correlated with the occurrence of blast transformation. CONCLUSION: Our data strongly implicate that prognostic classification of chronic-phase Ph(1+) CML can be significantly improved by the inclusion of morphologic parameters. The variables of the presented scoring system may be easily assessed by routinely processed aspirates and bone marrow trephines.

Initial (prefibrotic) stages of idiopathic (primary) myelofibrosis (IMF) - a clinicopathological study.

A clinicopathological follow-up study including sequential bone marrow biopsies was performed on 79 patients with idiopathic (primary) myelofibrosis (IMF) to characterize initial (prefibrotic) stages and to elucidate whether development of fibrosis was accompanied by corresponding clinical findings. For this purpose our cohort of patients was divided into two groups of which the first presented with the generally accepted signs and symptoms of IMF (group I; n = 60). Most patients of the second group (group II; n = 19) showed mild to moderate therapy-refractory anemia, minimal to slight splenomegaly and frequently thrombocytosis, but no bone marrow fibrosis at onset. Hematopoiesis was consistent with a striking hypercellularity in comparison to the age-related involution by adipose tissue, a conspicuous clustering and histotopographic dislocation of megakaryocytes, a neutrophil granulocytic proliferation and a reduction of erythropoietic islets with arrest of maturation. Most remarkable was the dysplastic cytology of megakaryocytes with a definitive deviation of differentiation resulting in bizarre forms. Follow-up examinations revealed that at later stages group II patients were not distinguishable from the first group with more advanced IMF. For this reason, these patients were regarded as presenting initial, prefibrotic IMF characterized by distinctive bone marrow features at the beginning. The prominent abnormalities of megakaryopoiesis together with the granulocytic proliferation were extremely helpful to differentiate prefibrotic IMF with accompanying thrombocythemia from essential thrombocythemia (ET). Dynamics of fiber progression were calculated by regarding increase in density per time. Speed of progression during the first year of observation proved to be significantly higher in group II patients with prefibrotic IMF in comparison to full-blown cases (group I). In conclusion, with respect to prospective clinical trials, diagnostic criteria for IMF should be re-evaluated by also taking initial, prefibrotic stages into account.

Polycythemia vera megakaryocytes but not megakaryocytes from normal controls and patients with smokers polyglobuly spontaneously express IL-6 and IL-6R and secrete IL-6.

Polycythemia rubra vera (PV) represents a clonal hematological disorder defined by an abnormal expansion of erythroid precursors and megakaryopoiesis, in particular. Ample evidence has been provided that the IL-6/1L-6R complex may be responsible for the proliferation of normal and neoplastic megakaryocytes in vitro and this fact lead us to the hypothesis, that defects in the regulation of IL-6 synthesis take part in the pathogenesis of PV. The study was carried out to determine the IL-6 serum levels and the megakaryocytic IL-6 production in patients with PV and to compare these data with the situation in hematologically healthy donors as well as in patients suffering from spurious polycythemia--smokers polyglobuly (PG). For this purpose, IL-6 serum levels were measured by ELISA and the megakaryocytic production studied by immunohistochemistry, reverse hemolytic plaque assay (RHPA) together with reverse transcription/polymerase chain reaction (RT-PCR) in highly enriched megakaryocyte preparations. In additional experiments, the influence of IL-3 stimulation and the expression of IL-6R were tested. Serum levels of IL-6 did not differ between the three groups under study. In contrast, immunohistochemistry revealed a raised proportion of megakaryocytes expressing IL-6 in PV as compared to normal donors and patients suffering from PG. The percentage of megakaryocytes actively secreting this cytokine as detected by the RHPA was 20 times greater than in both the other groups. This phenomenon was further substantiated by the fact that IL-6 mRNA could only be shown in PV megakaryocyte preparations. The regulation of IL-6 secretion appears to be abnormal in PV. Whereas in the normal and in the PG group IL-3 stimulation exerts a marked increase in megakaryocytic IL-6 secretion, PV megakaryocytes responded with a paradoxical down-regulation of IL-6 synthesis combined with the loss of IL-6R. Our data describe for the first time an abnormally raised IL-6 production by PV megakaryocytes and point towards fundamental regulatory alterations of the IL-6 synthesis in this disease.

Analysis of bcr rearrangements in primary (essential) thrombocythaemia.

A clinical and molecular study was performed on 10 patients with the presumptive diagnosis of primary thrombocythaemia (PTH). In all cases conspicuous megakaryocytic proliferation in bone marrow smears was detected in the absence of the Philadelphia chromosome (Ph1), elevated red blood cell mass and evidence for a reactive cause of the thrombocytosis. We analyzed whether rearrangements of the bcr gene occurred in untreated patients. Bcr rearrangements were detected in the bone marrow cells but not in peripheral blood bells of one patient, indicating that this case might be related at the molecular level with Philadelphia chromosome negative CML, in which bcr rearrangements could be demonstrated.

Polycythemia vera megakaryocytes store and release lysozyme to a higher extent than megakaryocytes in secondary polycythemia (polyglobuly).

Lysozyme, a myelomonocytic marker not only exerts bacteriolytic, but also immunomodulatoric properties and was found to bind to the glycosaminoglycan serglycin, an important constituent of the extracellular matrix (ECM). Pathological serum lysozyme levels were described in chronic myeloproliferative disorders (CMPDs) and other hematological conditions. In this context it is remarkable that in polycythemia rubra vera (PV), characterized by a proliferation particularly of the megakaryo- and erythropoiesis, serum lysozyme levels behave independently of the numbers of myelomonocytic cells in peripheral blood. To elucidate whether megakaryopoiesis might be the source of the increased serum lysozyme, we performed an experimental study on isolated and enriched megakaryocytes derived from bone marrow of patients with PV. Findings were compared to a group of patients with reactive (smoker's) polyglobuly (PG). In confirmation of previous results, quantification of serum lysozyme levels showed a slight elevation in the cohort of PV patients which was not correlated with the leukocyte count. Applying an immunohistochemical assay we were able to demonstrate intracytoplasmic lysozyme storage in megakaryocytes. Moreover, performing the reverse hemolytic plaque assay (RHPA), a technique which enables detection of secreted proteins at the single cell level, we found that 54% of the PV, but only 3% of the PG megakaryocytes spontaneously secreted lysozyme. After rhIL-3 treatment the secretion of lysozyme remained unchanged in PV but increased to 14% in PG. These findings suggest that the extent of megakaryocytic lysozyme secretion might discriminate PV from reactive conditions. Although a direct involvement of lysozyme in the regulation of aberrant megakaryopoiesis in PV is not likely, the results of the present study point to the possibility that lysozyme could be involved in the interactions of PV megakaryocytes with ECM. Moreover, the response to rhIL-3 significantly discriminates PV megakaryocytes from megakaryocytes of the PG group.

Effects of chemotherapy (busulfan-hydroxyurea) and interferon-alfa on bone marrow morphologic features in chronic myelogenous leukemia. Histochemical and morphometric study on sequential trephine biopsy specimens with special emphasis on dynamic features.

We performed a retrospective clinicopathologic study on sequential biopsy specimens from 90 patients with Philadelphia chromosome-positive chronic myelogenous leukemia to study therapy-specific effects of busulfan (28 patients), hydroxyurea (32 patients), and interferon-alfa (IFN-alfa; 30 patients). Bone marrow specimens were evaluated by morphometry after silver impregnation and staining with monoclonal antibodies to identify reticulin fibers, nucleated erythroid precursors, megakaryocytes, and macrophages. To compute dynamics of histopathology implicating corresponding changes in time, relevant indices were calculated. Quantification of megakaryocytopoiesis and its precursor cell population showed a significant increase in the IFN-alfa and busulfan groups compared with the hydroxyurea group. These changes were associated with a development of myelofibrosis during therapy. Although a significant increase in fiber density was detectable in the busulfan group, the progression index proved to be twice as high after IFN-alfa therapy. In contrast, a considerable number of patients displayed a regression of myelofibrosis after hydroxyurea treatment. The general association of the megakaryocyte lineage with myelofibrosis was in line with experimental findings. The mature macrophage population and its activated subfraction revealed a marked proliferation (IFN-alfa group) during treatment. Growth and activation of macrophages may be compatible with their putative function during erythrocytopoietic regeneration and with stimulation of their phagocytic properties.

Parameters of Predictive Value in Chronic Myeloid Leukemia-The Prognostic Impact of Histopathological Variables in a Multivariate Regression Analysis.

The prognostic significance of disease features at the time of diagnosis was examined in 113 patients (75 males/38 females, median age 49 years) with chronic myeloid leukemia (CML) using multivariate regression analysis. In the course of this study we tested the validity of the prognostic model described by Sokal and coworkers(3), the predictive value of histopathological variables, and determined the disease-specific loss in life expectancy. The median survival time was 35 months in our patients. By using Cox's proportional hazards model for covariate analysis of censored survival data(26)'(32) two prognostic models were derived. The first consisted of the following parameters-age, presence of pseudo-Gaucher cells in the marrow, spleen size and the product of myeloblasts and normoblasts in the peripheral blood. The second model included age, the presence of myelofibrosis, the number of megakaryocytes in the bone marrow and the liver size. Both models provided a risk status that showed an excellent predictive relationship to relative survival rates and life expectancy. Application of the Sokal model(3) to our subpopulation of CML patients failed to reveal a significant segregation of the intermediate group from the other risk groups, even when assessing the disease-specific loss in life expectancy. Our results suggest that an amendment of the generally accepted model for prognostic evaluation of survival in CML should be made by inclusion of histological variables and the determination of relative survival rates.

Early-stage idiopathic (primary) myelofibrosis--current issues of diagnostic features.

Idiopathic myelofibrosis (IMF) is generally characterized by bone marrow (BM) fibrosis, anemia, splenomegaly and a leuko-erythroblastic blood picture. Although, histopathology is in keeping with the assumption of a stepwise evolution of the disease, little hematological data are available for patients with prefibrotic and early stages of disease. Therefore a clinicopathological study was performed that included firstly an exploratory sample of 68 patients with minor supportive therapy in whom BM biopsies during follow-up (41 +/- 32 months) revealed an evolution of a prefibrotic or very early fibrotic lesion into overt IMF. The validation sample consisted of 556 patients with pretreatment marrow specimens on admission. Diagnostic features and BM lesions were identical compared with the patients of the exploratory sample at their first examination. BM biopsies were processed by routine stainings including silver impregnation (reticulin fibers) and frequently also by immunohistochemistry to identify megakaryocytes and erythroid precursor cells more properly. Apart from minor hemorrhage and peripheral thrombosis patients with early stage IMF presented with non-specific symptoms including varying degrees of leukocytosis (51%), anemia (38%), a platelet count exceeding 600 x 10(9)/l (86%), splenomegaly (15%) and increase in leukocyte alkaline phosphatase (LAP) (24%) and serum lactate dehydrogenase (LDH) (20%). BM histology confirmed a moderate increase in hematopoiesis with a mixed granulocytic and megakaryocytic myeloproliferation, a reduction of erythroid precursors and significant megakaryocytic abnormalities. In keeping with the first BM examination of the exploratory sample no or only a borderline to slight increase in reticulin fibers was detectable, however, in 68 of 134 patients follow-up biopsies revealed a transition into overt IMF (intervals about three years). Median survival of this cohort with early-stage IMF was 129 months thus contrasting manifest IMF with an usually more unfavorable prognosis. Recognition of early stage IMF certainly alters the generally applied diagnostic criteria of this disorder. Regarding patients with associated thrombocytosis, differentiation from essential thrombocythemia is recommended. Moreover, characterization of early stage IMF probably exerts an impact on survival and may influence the decision to perform a BM transplantation.

Idiopathic primary osteo-myelofibrosis: a clinico-pathological study on 208 patients with special emphasis on evolution of disease features, differentiation from essential thrombocythemia and variables of prognostic impact.

A retrospective clinico-pathological study was performed on 208 consecutively recruited patients (94 males, 114 females, median age 67 years) with idiopathic (primary) osteo-/ myelofibrosis (IMF). According to bone marrow histology (cellularity) as well as extent (semiquantitative grading) and quality (reticulin/collagen) of myelofibrosis, stages of the disease process were determined. At closure of this study (observation time 65 months) 133 patients were dead and 75 alive and median survival was 56 months. The wide spectrum of clinical signs and symptoms and laboratory data on admission was reflected by a corresponding variety of histological features. Significant differences of hematological values could be calculated between patients with or without early reticulin fibrosis (fiber scores 0 and 1) and advanced fibro-osteosclerotic stages (fiber scores 2 and 3). Evolution of disease features was elicited by longitudinal follow-up studies and sequential bone marrow biopsies. Morphometric assessment of fiber density in patients without preceding chemotherapy revealed an unpredictable and varying progression of myelofibrosis associated with alterations of certain laboratory parameters (hemoglobin level, spleensize, thrombocytosis). Differentiation from essential (primary) thrombocythemia (ET) was required in 25 patients who fulfilled the postulated diagnostic criteria. In fact, this group was consistent with hypercellular, early stages of IMF without relevant reticulin fibrosis and an excessively raised platelet count (> or = 1000 x 10(9)/1). Discrimination was only feasible by regarding histology carefully, particularly abnormalities of megakaryopoiesis and follow-up data. Parameters of predictive value indicating a significant loss in life expectancy in comparison with a sex- and age-adjusted normal population included: age (> or = 60 years), hemoglobin levels (< or = 10 g/dl), thrombocyte count (< or = 600 x 10(9)/1) and the presence of myeloblasts and promyelocytes. Statistical analysis disclosed that in the so-called early stages of IMF without relevant myelofibrosis, findings indicative for extramedullary hemopoiesis or generalization of the disease process exerted an unfavourable influence on survival.

Bone marrow features and clinical findings in chronic myeloid leukemia--a comparative, multicenter, immunohistological and morphometric study on 614 patients.

A multicenter, immunohistochemical and morphometric study was performed on diagnostic pretreatment bone marrow biopsies in 614 adult patients with Ph1+ chronic myeloid leukemia (CML) to compare histological features with clinical findings. For identification of megakaryopoiesis we used the monoclonal antibody CD61 and additionally the PAS reaction to determine the subfraction of atypical micromegakaryocytes and precursors. Labelling of erythroid precursors was carried out by a monoclonal antibody directed against glycophorin C. In order to selectively stain macrophages and their activated subset we applied CD68 and the GSA-I lectin. Density of argyrophilic fibers (reticulin plus collagen) was measured following Gomori's silver impregnation method. In accordance with laboratory data morphological variables revealed a comparable amount of congruence in the various groups of CML patients derived from different sources. In about 26% of patients early (reticulin) to advanced (collagen) fibrosis was detectable. Significant correlations were calculated between the extent of myelofibrosis with splenomegaly, anemia and increasing numbers of erythroblasts and myeloblasts in the peripheral blood count. These features were assumed to indicate more advanced stages of the disease process with ensuing transition into myeloid metaplasia and consequently were associated with an unfavorable prognosis. Significant relationships were revealed between the number of CD61+ megakaryocytes and more important, also their precursor fraction with the degree of fibrosis. This result extends previous experimental findings regarding the impact of immature elements of this cell lineage for the generation of myelofibrosis. The significant association of erythroid precursors with the number of mature (resident) macrophages including their activated GSA-I subset may shed some light on their functional involvement in iron turnover and hemoglobin synthesis. A modified histological classification of predominant bone marrow features is introduced. This simplified synthesis staging system (Cologne Classification) is not only associated with certain sets of laboratory data, but also with different survival patterns.

Primary myelofibrosis-osteomyelosclerosis (agnogenic myeloid metaplasia): correlation of clinical findings with bone marrow histopathology and prognosis.

A clinicopathological study was performed on 90 patients (39 males - 51 females, age 68 years) with primary (idiopathic) myelofibrosis - osteomyelosclerosis (OMF) in order to correlate laboratory and histomorphological parameters with each other and to calculate factors of prognostic impact on survival. In addition to multiple interactions between various laboratory features, there was a significant correlation between degree of medullary fibrosis and osteosclerotic changes with sizes of spleen and liver, level of LDH and duration of relevant prediagnostic symptoms. In trephine biopsies of the bone marrow, reduction of hematopoietic tissue was assessed by evaluating the amount of fat cells plus the degree of osteosclerotic lesions. This histological parameter did not reveal significant relationships with hepatosplenomegaly, duration of relevant symptoms or length of disease, but was correlated with the clinical findings of bone marrow failure. On univariate analysis, several clinical (age greater than 45 years, presence of relevant prediagnostic symptoms, hemoglobin level less than 9 g/dl, counts of myelo- and normoblasts, thrombocyte count less than 100 and greater than 700 x 10(9)/l, spleen size and LDH level) and histological features (reduction of hematopoiesis, counts for megakaryocytes and lymphoid nodules) were found to exert a predictive value on prognosis. However, on multivariate regression analysis only age remained significant. This result apparently reflects the numerous interactions between the various clinical as well as histological variables tested.

The prognostic implication of clinical and histological features in Ph1+ chronic myelocytic leukaemia (CML).

A study on clinical and histological features of prognostic significance was performed in 45 patients with Ph1+ -CML who showed median survival of 36 months. The histological features were evaluated by morphometry of iliac crest biopsies. Among the variables correlated with prognosis, we eliminated those without primary importance by mutual univariate retrospective stratification. Thus a clinical and a histological set of important prognostic criteria was established. Their influence on prognosis proved to be independent of each other and therefore could be used for separate classifications. Clinical classification yielded two groups with different prognosis: compared to the rest of the patients, the prognosis was much worse for those with a spleen size greater than 10 cm, a liver size greater than 2 cm (below costal margin) and greater than 5% circulating blasts plus promyelocytes. The histomorphological classification consisted of three subgroups: a better than average prognosis was found for patients with pseudo-Gaucher cells in the bone marrow, while in the remaining cases the prognosis was worse in patients with a high number of megakaryocytes (greater than 70/mm2) and a low volume ratio of granulopoiesis: megakaryocytes (less than 15). Since liver size was correlated with the duration of prediagnostic symptoms, the clinical classification probably reflects different disease stages, i.e. a later CML diagnosis. However, the histological set of prognostic factors is independent of the length of the prediagnostic period. Consequently, this morphological classification seems to discriminate different subgroups. Another important prognostic factor, marrow fibrosis, was independent of other histomorphological features, and correlated with duration of symptoms. It obviously also indicates more advanced disease.

Follow-up studies with sequential bone marrow biopsies in chronic myeloid leukaemia and so-called primary (idiopathic) osteo-myelofibrosis. Evolution of histopathological lesions and clinical course in 40 patients.

A clinicopathological follow-up study was performed on 17 patients with chronic myeloid leukaemia (CML) and 23 cases with so-called primary (idiopathic) osteo-/myelofibrosis (OMF) concentrating on a comparison between clinical data and multiple sequential biopsies of the bone marrow. Histological classification of bone marrow lesions was done according to the subtypes proposed by Georgii et al. At clinical diagnosis initial trephine biopsies in CML showed in only 6/17 cases a pronounced granulocytic proliferation or CGL. In 9/23 patients with OMF a so-called hyperplastic or early hypercellular stage was encountered with a mixed megakaryocytic-granulocytic pattern without or with minimal reticulin fibres (CMGM/EMS). The histopathology of this early stage OMF as well as the later evolving advanced fibrosclerotic lesions (AMS/OMS) were by morphological aspects alone not distinguishable from cases with CML showing prominent fibrosclerotic alterations. At presentation 5/17 patients with CML displayed already some degree of reticulin fibre formation (EMS). Following serial trephine biopsies in CML with an increased megakaryocyte proliferation (CMGM), a remarkable tendency for myelofibrosis was present. The dynamics of this fibrosclerotic transformation seem to be variable in CML and OMF likewise. However, they are related to abnormal megakaryopoiesis as well as to duration respectively progress of disease, paralleled by corresponding haematological parameters. This longitudinal case control study emphasizes that histopathology of the bone marrow taken at clinical diagnosis may reflect different stages of chronic myeloproliferative diseases and therefore should be always accompanied by relevant clinical and cytogenetic findings to enable a correct diagnosis.

Polycythemia rubra vera versus secondary polycythemias. A clinicopathological evaluation of distinctive features in 199 patients.

To determine parameters of distinctive value in polycythemia rubra vera (PV) versus secondary polycythemias (SP), a clinicopathological study was performed on 199 patients. These presented with a borderline to marked elevation of the hemoglobin level (> 18 g/dl in men and > 16 g/dl in women). Evaluations of clinical features and bone marrow histopathology were carried out independently. According to the results derived from laboratory data and representative pretreatment trephine biopsies, three groups of patients emerged: group I presenting with the concordant clinical and morphological findings of early to manifest PV (136 patients), group II consisting of 55 patients with the congruent signs and symptoms of SP mostly caused by various chronic bronchopulmonal disorders, and finally eight patients (group III) with divergent findings. Between group I and II patients (PV versus SP), a number of clinical parameters proved to be significantly different. With the exception, of the red cell mass, platelet count, leukocyte alkaline phosphatase, LDH, spleen size, and the erythropoietin level had a significantly discriminating impact. Morphological features of distinctive value consisted of a set of specific lesions. Contrasting SP with an only borderline to slight increase in cellularity associated with a moderate enlargement of the erythroblastic islets, PV was always characterized by a significant increase in hematopoiesis, revealing a trilinear proliferation (panmyelosis). Megakaryopoiesis was strikingly different in PV as compared to SP by displaying clustering and a pleomorphous appearance. i.e., very small and giant megakaryocytes with staghorn-like nuclei were neighboring each other. Moreover, conspicuous alterations of the interstitial compartment were recognizable in SP. These consisted of deposits of cell debris in histiocytic reticular cells, iron-laden macrophages, and a plasmacytosis, implying an inflammatory reaction. These changes were only very rarely observed in PV, as opposed to a minimal to slight increase in reticulin fibers in about 12% of patients. In conclusion, a more elaborate evaluation of bone marrow features resulted in a set of diagnostic criteria with discriminating capacity that should be considered in prospective clinical trials.

Osteoclasts and bone remodeling in chronic myeloproliferative disorders. A histochemical and morphometric study on trephine biopsies in 165 patients.

In 165 patients with chronic myeloproliferative disorders (CMPD) a morphometric and histochemical study was performed on trephine biopsies of the bone marrow to elucidate osseous remodeling by assessment of trabecular bone area (planimetry) and number of osteoclasts. Osteoclastic elements were identified by the tartrate-resistant acid phosphatase method. In addition to control specimens (n = 20) subtypes of CMPD included chronic myeloid leukemia (CML, n = 65), primary (essential) thrombocythemia (PTH, n = 25), polycythemia vera rubra (P. vera, n = 25) and agnogenic myeloid metaplasia (AMM, n = 50). AMM was discriminated into a so-called early hyperplastic stage without gross myelofibrosis (n = 19) and an overt or advanced stage showing fibro-osteosclerotic changes (n = 31). Total area of trabecular bone and counts for osteoclasts (uni- and multi-nucleated cells as well as a-nuclear cytoplasmic fragments) were not significantly increased in CML, PTH, P. vera and in the initial hypercellular stages of AMM. In contrast to these results, in advanced stages of AMM there was a significant increase in total bone area associated with a high count for all osteoclastic elements and apparently also an increased number of osteoblasts. It is speculated that the marked increase in osteoclastic-osteoblastic elements in late stages of AMM possibly reflects an imbalance of calcitriol (1.25-dihydroxyvitamin D 3) on skeletal homeostasis. This abnormal osseous remodeling may be mediated by the atypical megakaryocytic proliferation in this disorder, which is always a conspicuous feature of bone marrow biopsies.

Pro-megakaryoblasts in bone marrow tissue from patients with primary (idiopathic) osteo-myelofibrosis (agnogenic myeloid metaplasia). An immunomorphometric study on trephine biopsies.

An immunomorphometric study was performed on bone marrow biopsies from 40 patients with primary osteomyelofibrosis--OMF, (agnogenic myeloid metaplasia) by employment of a monoclonal antibody against glycoprotein IIIa (Y2/51) to determine the number of pro-megakaryoblasts. Specimens from 15 individuals without any hematological disorder served as controls. With reference to the pertinent literature on megakaryocyte precursors and following a pilot study on corresponding smears, in tissue sections pro-megakaryoblasts were characterized by a size of 42.1 +/- 2.6 microns 2 (diameter 7.5 +/- 0.3 microns). In comparison with controls, in OMF no relevant increase in the number of pro-megakaryoblasts per square and cubic millimeter bone marrow was evaluable. The relative frequency of these precursors was significantly reduced due to an increase in the total amount of conspicuously large and abnormal megakaryocytes. Statistical analysis failed to reveal any correlations between counts for pro-megakaryoblasts or the total number of Y2/51--positive megakaryocytic elements with the density of argyrophilic fibers (determined by morphometry) or the platelet values. Our findings imply that in OMF the marked increase in circulating progenitor cells of the megakaryocyte lineage may be generated by extramedullary, probably splenic hematopoiesis. Moreover, the evolution of medullary fibrosis is thought to be associated with the striking predominance of large atypical, possibly overaged and hyperpolyploid megakaryocytes and not with an increase in precursor cells.

[Primary malignant lymphoma of the stomach. Barium meal, sonography and computed tomography]. / Primäres malignes Lymphom des Magens. MDP, Sonographie, Computertomographie.

The features of barium meal, ultrasonography and CT in 18 patients with proven primary gastric lymphoma were analyzed retrospectively. Only barium meal could reveal highly suspicious features in 16 cases, whereas ultrasonography and CT showed a non specific wall thickening. Although single signs in a barium meal are non-specific, the combination of clubbing of mucosal folds, atypical ulcerations and extensive mural infiltration is highly suspicious of lymphomatous involvement. A negative barium meal, ultrasonography and/or CT result does not exclude gastric lymphoma.

[Bone marrow scintigraphy and magnetic resonance tomography in malignant lymphomas: comparison with histologic results]. / Knochenmarkszintigraphie und Kernspintomographie bei malignen Lymphomen: Vergleich mit histologischen Ergebnissen.

One hundred and seven patients with malignant Hodgkin and non-Hodgkin lymphoma were examined by bone marrow scintigraphy, MRI of bone marrow and bone marrow biopsy to detect bone marrow infiltration. The study included 2 patients where autopsy findings were subsequently available, 3 patients with blind rebiopsy and one patient with guided rebiopsy. The findings of bone marrow imaging and biopsy were classified as normal (grade 0), suggesting reactive changes of bone marrow (grade 1) or suspicious for infiltration (grade 2). About half of all results of biopsy and imaging methods agreed completely. There was a difference of two steps in the classification in only 2 cases (MRI) and 5 cases (scintigraphy). In patients with chronic lymphocytic leukemia false negative findings by both bone marrow imaging techniques were frequent. Unilateral blind bone marrow biopsy is usually accepted as the golden standard for the presence or absence of tumor infiltration. Although a positive biopsy result must be accepted as proof of bone marrow infiltration, our results indicate that a negative biopsy does not exclude tumor involvement. In all 4 patients with infiltration suspected on MRI or scintigraphy results but with normal findings or reactive changes in the first blind biopsy, blind rebiopsy or guided rebiopsy confirmed the results of the imaging methods. In both patients evaluated at autopsy the preceding MRI and scintigraphy results were confirmed completely, although in both of these patients antemortem biopsy had indicated different findings.(ABSTRACT TRUNCATED AT 250 WORDS)

[The prognostic significance of the differential blood count in patients with chronic myeloid leukemia]. / Die prognostische Bedeutung des Differentialblutbildes bei Patienten mit chronischer myeloischer Leukämie.

In 66 patients (37 male/29 female, median age 51 years) with CML in stable phase the initial smears of the peripheral blood were evaluated in regard to survival. Differential count was performed on 500 nucleated cells by two investigators working independently and blind. Scrutinized statistical analysis revealed not only the well-known predictive value of the number of myeloblasts, but also a significant prognostic impact for the percentages of polymorpho-nuclear granulocytes, eosinophils and basophils.