Subacute myelomonocytic leukemia. Clinical, morphologic and ultrastructural studies of 10 cases

A case-control study of chronic myelomonocytic leukemia (CMML) in Shanghai, China: evaluation of risk factors for CMML, with special focus on benzene

The authors report the results of a hospital-based case-control study of all patients diagnosed with chronic myelomonocytic leukemia (CMML) (n = 36) from 28 participating hospitals over a 4-year period. Diagnoses were made by a single laboratory using 2001 World Health Organization (WHO) criteria. Subjects were matched to 2 control patients and interviewed concerning previous diseases, work histories, and exposures to potential etiologic agents. Peripheral blood and bone marrow findings revealed clinical features of both myelodysplastic syndromes (MDSs) and myeloproliferative neoplasms (MPNs), consistent with hematopoietic disease category of MDS/MPN. The frequency of clonal cytogenetic abnormalities in all CMML cases was 31%, with no consistent pattern identified. A select number of risk factors associated with occupational exposure, nonoccupational exposure, and prior medical or family history of disease were extracted from the questionnaire. The results were compared between the case and control subjects. A total of 5 study subjects (2 CMML cases and 3 control subjects) were determined to have had some benzene exposure. In addition, none of the highlighted risk factors associated with nonoccupational exposure to etiologic agents was significantly different among the study subjects. These results do not support an increased risk for developing CMML associated with historical exposures to benzene.

Azathioprine and subacute myelomonocytic leukemia

The occurrence of subacute myelomonocytic leukemia is reported in a patient who had been treated with azathioprine for six years because of systemic lupus erythematosus. A review of the literature yielded 16 additional patients with non-lymphocytic leukemia after the use of azathioprine.

Juvenile chronic myelocytic leukemia--report of 10 cases

Ten children (five boys and five girls) with juvenile chronic myelocytic leukemia were seen over a period of 12 years (1980-1991) at the All India Institute of Medical Sciences, New Delhi. With the exception of one who was aged 4.5 years, all children were below 4 years of age (mean age 20.4 months). The presenting features included fever, bleeding secondary to thrombocytopenia, marked hepatosplenomegaly, and skin rash. The striking hematological features were anemia, thrombocytopenia, peripheral blood monocytosis, and normoblastemia. There was no significant myeloid proliferation in the bone marrow aspirate (mean M:E = 5:1), while erythroid proliferation was prominent along with monocytosis (mean 11.2%). Fetal hemoglobin was raised in 8 of the 10 patients (mean 14.1%). Long-term survival was poor, with maximum survival being 18 months in one case. New modalities of management of this rare entity are discussed.

Unusual cutaneous lesions associated with chronic myelomonocytic leukaemia

A 69-year-old man presented with unusual nodular cutaneous lesions of 3 years duration predominantly involving the chest, upper back and scalp. Histopathological changes in biopsy specimens from affected skin resembled those seen with granuloma annulare even though there was a lack of epithelioid cells. Based on the sluggish course of the condition, leukocytosis with monocytosis in peripheral blood and the findings on electron microscopic examination of peripheral blood cells, he was diagnosed as having chronic myelomonocytic leukaemia (CMMoL). At lower magnification under the electron microscope, the nodular skin lesions showed pleomorphic cell features with monocytes and histiocytic cells of abnormal appearance. The skin lesions were thus considered to be an unusual type of leukaemia cutis.

Treatment of myelodysplastic syndromes

Therapeutic options have been rapidly evolving for management of patients with the indolent myeloid clonal hemopathies termed myelodysplastic syndromes (MDS). Heterogeneity of MDS has been demonstrated on the basis of marrow morphology and biologic features and has been useful for prognostication into high and low risk groups for transformation to acute leukemia. Such stratification has been important for evaluating responses to various treatments. These therapeutic options include the differentiation-inducing vitamins retinoic acid and vitamin D, and cytokines such as alpha and gamma interferon, to which there has been a generally low response. The use of intensive or low dose chemotherapy has been associated with relatively low response rates, few durable responses and a high degree of hemopoietic toxicity. Allogeneic bone marrow transplantation (BMT) has shown durable responses for a subset of MDS patients, particularly those who are young and who are in the low risk subgroups. however, due to the elderly nature of the majority of MDS patients, and the toxicity associated with BMT, this option has limited utility for most of these patients. Major focus has been on the recent therapeutic use of recombinant human hemopoietic growth factors, particularly G-CSF, GM-CSF and IL3. These agents have been well-tolerated and generally produce a high incidence of sustained improvements in neutrophil counts and marrow morphology, although hemoglobin and platelet counts have generally not been altered. More extensive clinical trials evaluating the impact of these hemopoietic growth factors on the natural history of MDS are ongoing.

Prognostic factors and survival in chronic myelomonocytic leukaemia (CMML)

Ninety-seven cases of chronic myelomonocytic leukaemia (CMML) were examined retrospectively for survival and possible prognostic factors including age, total white cell count, peripheral blood and bone marrow monocyte counts, % double esterase (DE) positive cells in bone marrow and serum lysozyme. Age, absolute monocyte counts and serum lysozyme proved to be significant independent prognostic indicators but Cox model analyses showed serum lysozyme to be the most important factor whether taken as a continuous or discrete (two groups) variable. Twelve cases of second malignancy were found, including 2 cases of multiple myeloma, but this was not significantly greater than expected when compared with an age and sex matched group.

Chronic and subacute myelomonocytic leukaemia in the adult: a report of 60 cases with special reference to prognostic factors

We report 60 cases of chronic and subacute myelomonocytic leukaemias (CMML and SMML) in the adult, using the FAB group criteria. The M/F sex ratio was 3.3 and the mean age 67.5 years. Splenomegaly was found in 32% of cases, hyperleucocytosis in 52% of cases and mean blood monocytosis was 4.3 X 10(9)/l. Marrow smears showed an excess of blasts in 57% of patients, a moderate increase in monocytes in most cases and frequent myelodysplastic features. An increase in serum lysozyme and polyclonal hypergammaglobulinaemia were usual and clonal cytogenetic anomalies found in about half of the patients tested. Treatment was usually palliative and the median survival was 28 months, a blastic transformation being responsible for a third of the deaths. Prognostic factors at diagnosis were analysed retrospectively in the 46 patients who had sufficient follow up. Percentage of marrow blasts haemoglobin level and blood monocytosis at diagnosis, were subject to multivariate analysis, resulting in a discriminant 'score'. This allowed assignment of each patient into one of two prognostic subgroups (10.9% probability of error): a poor prognosis one, with a life expectancy of less than 1 year and a high risk of acute transformation (subgroup termed SMML) and a better prognosis subgroup (termed CMML), with some CMML patients surviving over 5 years.

Management of myelodysplastic syndromes

The treatment of myelodysplastic syndromes is reviewed, with emphasis on recently published clinical trials. Pyridoxine is rarely effective, but a trial in patients with refractory anemia with ringed sideroblasts is justifiable. Corticosteroids do not appear indicated unless in vitro data suggest response. Androgens are generally not beneficial, although danazol merits further evaluation. Both 13-cis-retinoic acid and low-dose cytosine arabinoside have considerable toxicity and yield short-lived partial responses that may not have a significant impact on survival. Combination chemotherapy may be considered in selected patients with refractory anemia with excess of blasts, refractory anemia with excess of blasts in transformation, and chronic myelomonocytic leukemia; however, in general, its toxicity outweighs potential benefit. For unusual patients under 30 years old, bone marrow transplantation should be considered as first-line therapy. Until more effective and less toxic agents are available, supportive care may still be the most appropriate therapy for many of these generally elderly patients.

Prognostic factors for survival of 194 patients with low infiltrate leukemia

Prognostic factors were identified from the histories of 194 patients diagnosed as having low infiltrate leukemia (LIL) between 1973 and 1981, when the policy was to delay treatment until there was evidence of progressive disease or life-threatening morbidity. Their median age was 59 yr; 63% were male; 30 had had a malignant disease previously. Presenting symptoms included anemia, 82%; infections, 15%; and hemorrhage, 16%. The group's median survival was 42 weeks, with high marrow cellularity and percentage of blasts, impairment of bone marrow, liver or renal function, age over 65 yr and performance status less than 80% associated with poorer survival. Cytogenetic changes associated with poor survival included loss of chromosome 5 or 7, additional chromosome 8, karyotypic instability, and presence of 100% abnormal metaphases. A regression model including terms for blood and bone marrow features, and age at hospital admission was able to stratify patients into prognostic groups in the same population and in an independent population admitted prior to 1973. Further prospective testing of the model is required. Twenty-six of the 78 patients who were eventually treated with combination chemotherapy achieved complete remission. The presence of Auer rods, diagnosis of acute leukemia or refractory anemia with excess blasts, rapid increase in marrow infiltrate and favorable cytogenetic karyotype were associated with response. Delaying treatment in all patients was found to have improved only modestly the survival of patients with LIL.

The concept of preleukemia: clinical and laboratory studies

Thirty-five years ago, a handful of astute clinical hematologists began to notice that some of their patients with acute nonlymphocytic leukemia had a history of a preceding ill-defined hemopathy. This "preleukemic" hemopathy was increasingly reported anecdotally and through careful retrospective analyses. In more recent prospective studies, this syndrome has been relatively well defined. Indeed, it is widely accepted that there exists a hematopoietic abnormality not recognizable as classical, overt, acute nonlymphocytic leukemia, which, nonetheless, can represent an early phase of leukemia. In this manuscript, the author reviews the original case reports, the initial retrospective studies, and the prospective studies which have clarified some of the clinical and laboratory features of the preleukemic syndrome. The notion that the preleukemic syndrome represents an established neoplastic process will be reviewed with special attention to assessment of clonal hematopoiesis, cytogenetic studies, and clonal evolution. Studies on induced leukemia and preleukemia in experimental animals and humans will be reviewed as will be the semantic issues which have complicated our ability to compare interinstitutional studies. A simple classification scheme of the myelodysplastic syndromes will be presented as will be a framework agenda for future studies on the pathophysiology of these syndromes.

Specific cutaneous involvement in the course of chronic myelomonocytic leukemia simultaneously with blastic leukemic transformation. Report of a case with histologic and cytochemical study

We report a case, in a 74-year-old man, of chronic myelomonocytic leukemia (CMML) that showed cutaneous involvement in its terminal phase. The patient developed a nodular eruption with an irregular distribution over the entire skin surface. Histology showed an acute leukemic infiltration in the reticular dermis. We were able to demonstrate cells with intermediate myeloid and monocytic characteristics ("paramyeloid cells") in the skin biopsy and in bone marrow smears. There have been only four patients reported previously with similar clinical findings. In one of them the cutaneous eruption heralded an aggressive clinical shift of the disease, as in our case. The present case confirms the utility of skin biopsy in similar cases for predicting the evolution of the disease.

Chronic myelomonocytic leukemia: clinical features, cytogenetics, and prognosis in 30 consecutive cases

A retrospective analysis of 30 patients with chronic myelomonocytic leukemia (CrMML) was performed to define the natural history of the disease and the risk of acute transformation. Our patients fulfilled the following criteria of diagnosis: blood monocytosis over 1 X 10(9)/l, blast cell percentage in bone marrow up to 30, and in peripheral blood less than 5. The most common presenting feature was anemia; seven patients had fever; three patients complained of purpura and bleeding. Anysopoikilocytosis and macrocytosis were frequent. Abnormal granulocyte morphology, defective granulation and abnormal leukocyte alkaline phosphatase were often observed. Blast cells in peripheral blood smears were found in 14 patients. Serum and urine lysozyme levels were increased in 82 per cent and 93 per cent, respectively. Dysplastic changes involving erythroid, granulocytic and megakaryocytic lineages were constant features in all cases. Agranulated blasts above 5 per cent of marrow nucleated cells were seen in 13 patients (43 per cent). Seven of the 20 patients showed non-specific chromosomal abnormalities at diagnosis. Median survival from diagnosis was 18 months (range, 3-112). Evolution into acute myeloid leukemia occurred in 11 patients. No difference in survival was found between patients who developed acute leukemia and patients who did not. A shorter survival has correlated to the following parameters: leukocytes greater than 10 X 10(9)/l, the presence of blasts in peripheral blood and agranulated blasts in the marrow above 5 per cent.

Serous effusions in monocytic leukaemias

We report four patients who either presented with or developed serous effusions during the course of monocytic leukaemia. This finding has not been documented previously. All the patients had very high peripheral blood monocyte counts when effusions developed. The effusions resolved after the patients were treated with anti-leukaemic therapy. It is therefore likely that the effusions were disease related. Two of the patients have been treated with razoxane, one with etoposide and the other with cytarabine.

Subacute and chronic myelomonocytic leukemia in children (juvenile CML). Clinical and hematologic observations, and identification of prognostic factors

The clinical and hematologic characteristics of 38 children with subacute and chronic myelomonocytic leukemia (S & CMMOL) are described, and the prognostic significance of these characteristics as recorded at diagnosis is reported. The common and distinctive feature of these children was the excessive proliferation of cells of neutrophilic and monocytic series. The disease predominated in younger children, 95% were younger than 4 years, and boys were more affected than girls (22/16). The onset of the disease was heralded most often by acute or subacute symptoms. Splenomegaly was the most common physical finding at diagnosis. Leukocytosis was usually under 100 X 10(9)/l. Monocytosis and granulocytosis were often associated with normoblastosis, and, in some cases, with moderate blastosis (less than or equal to 30%). Severe anemia and marked thrombocytopenia were found in about one third of patients, increased fetal hemoglobin levels in 53%, and increased gamma-globulin levels in 50% of cases. The Philadelphia chromosome was absent in all blood and marrow cell karyotypes. Thirty-three of 38 patients were treated with moderate or intensive chemotherapy, and in all cases treatment never resulted in a complete remission. Terminal acute leukemia occurred in 11 cases. Of the 38 patients, 29 have died (median survival time, 16 months). Initial characteristics predicting a short survival (log-rank test) included: older age (greater than or equal to 2 years) (P less than 0.001), hepatomegaly (P less than 0.05), bleeding (P less than 0.001), thrombocytopenia (P less than 0.01), high counts of blasts and normoblasts in peripheral blood (P less than 0.01, P less than 0.01). Sex, infections, cutaneous manifestations, lymphadenopathy, degree of splenomegaly, hemoglobin levels, fetal hemoglobin, leukocyte counts, percent of blasts in bone marrow, and serum gamma-globulin levels were of no prognostic value. When survival was plotted on a semilogarithmic scale, a change in death rate was evident at the second year of survival suggesting that there may be two subgroups of patients with myelomonocytic picture, one with very rapid, and another with a slower rate of mortality. A stepwise discriminant-function analysis was performed in an attempt to distinguish between those children who lived less than or equal to 2 years and those who lived longer. A linear combination of variables which best discriminated between these two subgroups was found. Nearly all patients could be classified as a short-survivor or long-survivor on the basis of age and platelet, blast, and normoblast counts in peripheral blood.(ABSTRACT TRUNCATED AT 400 WORDS)

Chronic myelomonocytic leukemia: value of touch preps

(CMML) Chronic myelomonocytic leukemia is not an uncommon leukemia occurring in elderly individuals. Cutaneous manifestations are unusual and portend a poorer prognosis. Touch imprints from a skin punch biopsy may help to quickly confirm clinical suspicions of an underlying leukemia or lymphoma.

Skin infiltration associated with chronic myelomonocytic leukaemia

Chronic myelomonocytic leukaemia (CMML) is typically associated with a prolonged clinical course and is not usually very responsive to chemotherapeutic intervention. Skin infiltration has not been recognized previously as a feature of this illness. We have seen four patients recently with CMML, who during the the course of their illness developed marked skin infiltration. Whilst sensitivity to chemotherapy could be demonstrated in the peripheral blood cell population, skin infiltration was quite resistant to treatment. Skin infiltration heralded a more aggressive phase of the disease although no discernible change in morphology, cytochemistry or membrane marker analysis of the leukaemic cell population could be demonstrated in three of the patients studied; one patient, however, transformed to an acute leukaemia shortly thereafter.

Cytogenetic findings in the dysmyelopoietic syndrome

Cytogenetic studies of bone marrow specimens from 15 patients with dysmyelopoietic syndrome are presented. The group consists of nine patients with refractory anemia with excess of blasts (RAEB), three patients with chronic myelomonocytic leukemia (CMMoL), and three patients with acquired idiopathic sideroblastic anemia (AISA). None of these patients had a prior history of therapeutic or occupational exposure to potential carcinogenic agents, G(TG)-banding revealed clonal abnormalities in nine of the 15 patients. Five of these patients exhibited one or more of the following cytogenetic abnormalities: 5q deletion, -7, +8, or +21. The AISA group appeared to be unique as chromosome abnormalities were seen in two of the three patients and the clinical course in these patients had been prolonged without progression to acute leukemia. No other clinical correlation could be made in the blast RAEB and CMMoL groups, except for possible survival benefit in patients with normal karyotypes.

Chronic monocytic leukemia in adults

Clinical, hematologic, and histologic material from five patients with chronic monocytic leukemia is analyzed, and the literature is reviewed on 28 patients either reported as having this disease or referenced as such in subsequent publications. Patients with chronic monocytic leukemia have a characteristic clinical course. All have splenomegaly of uncertain etiology, and initial hematologic evaluation usually shows anemia with normal leukocyte and differential counts. One of the authors' patients had slight monocytosis at presentation. In the four patients for whom presplenectomy bone marrow smears were available for review, there was no detectable increase in the number of monocytes. The patients developed monocytosis, usually with accompanying leukocytosis, at intervals ranging from 3.5 to 24 months after splenectomy. In all patients, there was a corresponding increase in the numbers of mature monocytes in the bone marrow. Survival times from the detection of monocytosis ranged from five to eight months. Of the 28 cases reported in the literature, only two were considered by the authors of this study to have the characteristics of chronic monocytic leukemia, and of these, only one had features identical to those reported in the present series. The remainder represent a variety of hematologic disorders including chronic myelomonocytic leukemia, acute leukemia, histiomonocytic proliferations that cannot be sub-classified, and cases in which the data are insufficient for analysis. The differential diagnosis includes chronic myelomonocytic leukemia, chronic malignant histiocytosis, and hairy cell leukemia. In chronic monocytic leukemia, in contrast to hairy cell leukemia, splenectomy does not appear to be beneficial. Although chronic monocytic leukemia is an extremely rare disease, it is a distinct hematologic entity that appears to have a characteristic clinical course.

Chronic myelomonocytic leukemia in childhood

A four-year-old child with recurrent infections and increasing hepatosplenomegaly over a three-year period was evaluated. Increased numbers of myeloid precursors packed the bone marrow and infiltrated the peripheral blood. A diagnosis of chronic myelogenous leukemia (CML) was considered but could not be confirmed by laboratory studies appropriate for the types of CML usually observed in childhood. Examination of the patient's peripheral blood smears revealed many atypical monocytoid cells with unipolar hairy projections. Scanning electron microscopy showed these to be leukemic monoblasts with characteristic broad-based ruffles on the cell surface. A population of myeloid precursors possessing narrow ridge-like profiles was also observed. Progressive infiltration of the spleen caused hypersplenism which necessitated splenectomy. Subsequently, massive liver and bone marrow involvement led to the patient's death. Terminally, the proliferating blast cells were demonstrated to be leukemic monoblasts by analysis of cytochemical staining patterns, surface immunoglobulins, serum lysozyme levels, and monocyte-mediated antibody-dependent cellular cytotoxicity studies. The findings in this case are most compatible with a diagnosis of chronic myelomonocytic leukemia (CMML), a condition not previously described in childhood. Several myeloproliferative disorders with prolonged survival have been reported in children, but special studies were not performed to determine which cell lines were abnormally proliferating. The similarities between these children and our patient with CMML suggest that monocyte studies may be useful in the diagnosis of these unusual disorders, provide insights into their pathogenesis, and aid in the selection of appropriate therapy.

Adult acute nonlymphocytic leukemias

For the first two decades, leukemic chemotherapy had little impact on survival. In the past 10 years, however, remission induction therapy has generated complete remissions which last approximately one year in about half to three fourths of those treated, with a seventh in some series alive at 5 years.

Pruritus and nonspecific nodules preceding myelomonocytic leukemia

Subacute myelomonocytic leukemia is typically preceded by a preleukemic phase lasting 1 to 10 years. We describe a case of subacute myelomonocytic leukemia preceded by pruritus for 7 years and by the intermittent appearance of nonspecific necrotic dermal nodules for 4 years.

Monocytic leukemias

The monocytic leukemias may be subdivided into acute monocytic leukemia, acute myelomonocytic leukemia, and subacute and chronic myelomonocytic leukemia. The clinical features of acute monocytic and acute myelomonocytic leukemias are similar and are manifestations of bone marrow failure. Gingival hypertrophy and skin infiltration are more frequent in acute monocytic leukemia. Cytomorphologically the blast cells in acute monocytic leukemia may be undifferentiated or differentiated, whereas in the acute myelomonocytic variety there are mixed populations of monocytic and myeloblastic cells. Cytochemical characteristics include strongly positive reactions for nonspecific esterase, inhibited by fluoride. The functional characteristics of acute monocytic and acute myelomonocytic cells resemble those of monocytes and include glass adherence and phagocytoses, the presence of Fc receptors for IgG and C'3, and the production of colony stimulating activity. Subacute and chronic myelomonocytic leukemias are insidious and slowly progressive diseases characterized by anemia and peripheral blood monocytosis. Atypical monocytes called paramyeloid cells are characteristic. The drugs used in the treatment of acute monocytic and acute myelomonocytic leukemias include cytosine arabinoside, the anthracyclines, and VP 16-213. Drug therapy in subacute and chronic myelomonocytic leukemias is not usually indicated, although VP 16-213 has been claimed to be effective.

Disseminated coagulopathy in chronic myelomonocytic leukemia

The clinical and laboratory features of nine patients with chronic myelomonocytic leukemia are described. Hepatic or splenic enlargement accompanied by an absolute monocytosis in an older patient with an elevated serum or urine lysozyme and serum vitamin B12 levels were characteristic of the majority of patients in this series. No single clinical or laboratory finding was diagnostic for the disease. Most importantly, seven of nine patients had abnormal coagulation values; in two cases the abnormalities were consistent with disseminated intravascular coagulation and correlated with a hemorrhagic diathesis. It is concluded that patients with chronic myelomonocytic leukemia who have thrombocytopenia or a bleeding tendency should be evaluated for evidence of disseminated intravascular coagulation.

Subacute myeloid leukemia: a clinical review

The data on 31 patients who fit into the clinical spectrum of subacute myeloid leukemia have been reviewed. The majority of patients were male with a median age of 61 years. The interval from onset of symptoms to actual diagnosis was extremely variable, with a mean of 16 months and a median of six months. Most patients presented with anemia and thrombocytopenia, although the white blood cell count varied from striking leukopenia to marked leukocytosis. Examination of the bone marrow invariably revealed abnormalities of all cell lines with megaloblastoid erythrogenesis and dysplastic megakaryocytopoiesis. Although the white cell line showed prominence of immature forms, there was more maturation than is seen in acute myeloid leukemia. Survival from diagnosis was variable, from less than one month to greater than 68 months, with a median of only six months. Anemia and hepatosplenomegaly were prognosticators of a poor outlook; patients with hepatosplenomegaly in association with either leukocytosis or thrombocytopenia had a particularly poor outlook, with a median survival of only one and a half months. Approximately half the patients received chemotherapy with no demonstrated effect on survival.

New aspects of preleukemic disorders

Preleukemic disorders are a controversial group of panmyelopathic disturbances that often precede the emergence of acute myeloblastic or myelomonocytic leukemia. In most instances, these preleukemic disorders are characterized by slowly developing myeloblastosis of the bone marrow. They include preleukemia, primary acquired panmyelopathy with myeloblastosis or smouldering acute leukemia, erythroleukemia, and subacute myelomonocytic leukemia. Sometimes, transitions between these various preleukemic disorders may be observed in a single individual. Abnormalities in cellular differentiation are expressed in cytochemical aberrations and in elaboration of colony forming units by marrow cells of patients with preleukemic disorders. Cytogenic and cellular kinetic abnormalities link preleukemic disorders closely to acute myeloblastic or myelomonocytic leukemia, although in many patients with preleukemic disorders, conversion to acute leukemia is not observed or perhaps not recognized. Understanding pathogenetic and pathophysiological aspects of preleukemic disorders may shed light on aspects of cellular proliferation and cellular differentiation in the acute leukemias.

[Myelomonocytic leukemia: clinical, cytological, and cytogenetic studies of acute, subacute, and chronic forms (author's transl)]

44 patients suffering from myelomonocytic leukemia (MML) have been observed over the last four years. They have been subclassified in acute myelomonocytic and acute monoblastic leukemias (AMML, n = 12; AMoL, n = 10), subacute myelomonocytic leukemias (SMML, n = 13), and chronic myelomonocytic leukemias (CMML, n = 9) on the basis of bone marrow cytology(blast and promonocyte counts, maturation of granulopoesis) and cytochemical findings (peroxydase and unspecific esterase reaction). This subclassification has been proved to be of prognostic relevance by its good correlation with the mean survival times (AMML : 4.5 months, AMoL : 2.4 months, SMML : 8 months, CMML : 18 months). The acute forms have been treated in general with combined cytostatic chemotherapy, whereas SMML and CMML have been treated this way only in case of progression to an acute phase. These progressions to an AMML have been observed more often and earlier in subacute forms than in chronic forms. The diagnosis of SMML and CMML is supported by the finding of sea-blue histiocytes in the bone marrow, increased lysozyme levels in serum and urine and by the absence of the Philadelphia-Chromosome.

Intracellular lysozyme and lactoferrin in myeloproliferative disorders

Samples from 49 cases of myeloproliferative diseases were tested by an immunocytochemical technique for leucocyte lysozyme and lactoferrin. The presence of these constituents in myeloid precursors from cases of acute and chronic myeloid leukaemia reflected the degree of cellular maturation, lysozyme appearing (as it does in normal myeloid cells) at the stage of primary granule production (in promyelocytes), while lactoferrin wad detectable only in more mature, secondary granule-containing myeloid cells. Auer rods stained positively for lysozyme, in keeping with their relationship to primary granules. Monocytes from five cases of leukaemia showing predominantly monocytic differentiation were indistinguishable from normal monocytes in their staining reactions for lysozyme despite the presence of raised serum and urinary lysozyme levels. In four cases of acute myeloid leukaemia circulating polymorphs deficient in lactoferrin were detected: in one of these cases a similar percentage of polymorphs was lysozyme negative.

The myeloproliferative disorders. Correlation between clinical evolution and alterations of granulopoiesis

Patients with myeloproliferative disorders were prospectively studied by in vitro agar-gel marrow culture technics to evaluate factors involved in the evolution of abnormal granulopoiesis. Marrow granulocytic colony-forming capacity was determined in 78 patients with chronic myeloid leukemia, subacute myeloid leukemia, preleukemia, Di Guglielmo's syndrome, polycythemia vera or essential thrombocythemia. A wide range of marrow colony-forming capacity values was noted early in disease courses; however, in 26 of 33 patients decreased colony-forming capacity was associated with disease transformation into acute myeloid leukemia or other clinically aggressive stages. An increased proportion of abnormally light buoyant density (less than 1.062 g/cm3) colony-forming cells was present in the marrow and peripheral blood of 15 of 16 patients with chronic myeloid leukemia, subacute myeloid leukemia, preleukemia or essential thrombocythemia; in seven of eight patients with greater than 35 per cent abnormally light colony-forming cells their disease subsequently underwent transformation. Elevated levels of urinary colony-stimulating factor output were noted in 17 of 31 patients, and in 10 of 12 patients whose disease subsequently underwent acute transformation within 10 months of study. In six of seven patients who simultaneously had an increased urinary output of colony-stimulating factor and low colony-forming capacity in marrow, transformation occurred within 10 months. These findings indicate that progressive abnormalities of both marrow clonal growth patterns and levels of possible humoral regulatory substances develop during evolution of these diseases. In contrast, patients with idiopathic sideroblastic ineffective erythropoiesis had normal values for marrow colony-forming capacity, proportion of light density colony-forming cells and urinary colony-stimulating factor output, and in none has their disease transformed into acute myeloid leukemia. These in vitro studies appear useful for clinical staging, evaluating prognosis and categorizing patients with myeloproliferative disorders.