Extramedullary presentation of the blast crisis of chronic myelogenous leukaemia

Cytopathology of myeloid sarcoma: a study of 16 cases

INTRODUCTION

The diagnosis of myeloid sarcoma (MS) in cytology samples is challenging, especially when these tumors occur prior to a diagnosis of acute myeloid leukemia. The aim of this study was to review our cytopathology service's experience with a series of MS cases.

MATERIALS AND METHODS

Archival records were searched from which 16 cytology cases of MS were identified and reviewed. Clinical findings, cytomorphology, and ancillary studies were analyzed.

RESULTS

MS was secondary to acute myeloid leukemia in 14 cases, chronic myeloid leukemia (CML) in blast crisis in 1 case, and myelodysplastic syndrome in another. Flow cytometry was supportive in 11 cases, immunostains were helpful when performed in 4 cases, and fluorescence in-situ hybridization in the CML case showed t(9;22). Cellularity was variable in all leukemia subtypes. Blasts had round or cleaved nuclei with indistinct nucleoli. Maturing granulocytes were present only in the patient with CML, or with peripheral blood contamination (4 cases). Other blood precursors were absent. Apoptosis and lymphoglandular bodies were present in almost one-half of the cases, which correlated with increased blasts. Mitoses were infrequent (6 cases) and necrosis was not seen.

CONCLUSIONS

The diagnosis of MS in cytology specimens can be made in cases with adequate cellularity and supportive ancillary studies in the correct clinical context. MS was harder to diagnose in cytology cases with low cellularity, blood contamination, and few blasts. Cytologic features that pose diagnostic pitfalls are lymphoglandular bodies suggestive of lymphoma and maturing or mixed granulocytes that mimic infection.

New insights into the pathobiology and treatment of chronic myelogenous leukemia

Chronic myelogenous leukemia (CML) is one of the most frequently diagnosed forms of leukemia. Recent advances in the understanding of the molecular mechanisms involved in the pathogenesis of this disorder led to new diagnostic and therapeutic approaches. From a disease that used to be diagnosed purely on morphologic grounds, CML is now an entity that cannot be diagnosed in the absence of relevant cytogenetic or molecular data. Identification of the characteristic t(9;22) cytogenetic abnormality or of the BCR-ABL molecular abnormality is mandatory, as current treatment approaches rely on the use of agents active against this specific molecular target. This article presents the evolution in the understanding of the pathogenic mechanisms involved in CML, as well as the methods and the criteria currently in use in its diagnosis and treatment.

Case of chronic-phase chronic myelogenous leukemia with an abdominal hematopoietic tumor of leukemic clone origin

We report a 59-year-old man with chronic myelogenous leukemia (CML) in chronic phase who presented with a large abdominal tumor. Biopsy revealed proliferation of granulocytic-, erythroid-, and megakaryocytic-lineage cells in a retroperitoneal lymph node. The BCR/ABL fusion gene was detected on a paraffin-embedded tissue section of the lymph node by double-color fluorescence in situ hybridization, indicating an extramedullary hematopoietic tumor of CML origin. This patient has achieved a complete cytogenetic response for 19 months with imatinib mesylate (STI571; Gleevec), in association with the regression of the tumor. However, the development of an extramedullary tumor in chronic-phase CML generally indicates a poor prognosis, because it commonly consists of blast proliferation and is followed by blast crisis in the marrow within a few months. This case, therefore, points to the importance of histological examination of extramedullary tumors in CML for evaluation of disease status and for therapeutic decisions.

Extramedullary blast crisis in a patient with chronic myelogenous leukemia in complete cytogenetic and molecular remission on interferon-alpha therapy

We report the previously undescribed occurrence of extramedullary blast crisis in a patient with chronic myelogenous leukemia in complete cytogenetic and molecular remission on interferon-alpha. Development of bilateral testicular swelling prompted a biopsy showing stromal infiltration with CD20 and TdT positive immature cells. On repeated examinations, the bone marrow remained BCR/ABL negative by RT-PCR analysis. However, the cerebrospinal fluid (CSF) contained atypical lymphocytes positive for the P210 BCR-ABL product. Following treatment with testicular irradiation, intrathecal methotrexate, systemic chemotherapy and an unrelated donor transplant, the patient showed no evidence of disease until 9 months post-transplant, when he relapsed in lymphoid blast crisis in both bone marrow and CSF.

Ph-negative non-Hodgkin's lymphoma occurring in chronic phase of Ph-positive chronic myelogenous leukemia is defined as a genetically different neoplasm from extramedullary localized blast crisis: report of two cases and review of the literature

This report describes two cases of Philadelphia chromosome-negative (Ph(-)) non-Hodgkin's lymphomas (NHLs) recognized in patients with chronic phase Ph-positive (Ph(+)) chronic myelogenous leukemia (CML). Lymph node biopsy of patient 1 was initially diagnosed as diffuse large B cell non-Hodgkin's lymphoma (NHL, T cell rich variant), but at relapse showed immunoblastic features with a marked decrease of admixed lymphocyte components. Patient 2 presented with thickened parietal pleura which revealed a CD30-positive anaplastic large cell lymphoma showing null cell phenotype and genotype with abundant admixed neutrophils and lymphocytes. At the time of lymphoma diagnosis, the patients had CML for 33 and 10 months, respectively. DNA obtained from bone marrow cells at the time of lymphoma diagnosis showed BCR/ABL gene rearrangements by both Southern blot analysis and reverse transcription polymerase chain reaction (RT-PCR), but lacked both immunoglobulin and T cell receptor gene rearrangements. BCR gene rearrangement and BCR/ABL fusion gene were also identified in lymph node and pleural biopsies by Southern blot and RT-PCR analysis, respectively. However, both biopsy specimens also contained reactive lymphocytes and neutrophils, and no fusion signals between BCR and ABL genes were identified in the hyperdiploid lymphoma cells of either case by fluorescence in situ hybridization (FISH). These data suggest the lymphoma cells in both cases were not genetically associated with BCR/ABL. Therefore, these cases were not diagnosed as an extramedullary localized blast crisis in CML, but as Ph(-) NHLs. This represents the first definitive demonstration of peripheral B cell lymphoma occurring by a separate genetic pathway, lacking BCR/ABL, in patients with Ph(+) CML. A review of the literature identified two different subtypes of malignant lymphomas arising in patients with an antecedent or concurrent diagnosis of CML. The most common are T cell lymphomas displaying an immature thymic phenotype, while peripheral B cell lymphomas are more rare. Our study shows, however, that 'Ph(+) NHL' occurring in CML or acute lymphocytic leukemia (ALL) may represent an unrelated neoplasm, even if standard cytogenetic analysis reveals a Ph(+) chromosome, and that FISH is required to confirm whether a localized lymphoid neoplasm is either a true extramedullary localized blast crisis or genetically distinct neoplasm. Leukemia(2000) 14, 169-182.

Extramedullary presentation of chronic myelogenous leukemia with p190 BCR/ABL transcripts

We present here a rare case of Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia having p190 BCR/ABL with a malignant clinical picture of extramedullary blast crisis at onset, followed by rapid evolution to bone-marrow blast crisis. The patient was a 44-year-old woman presenting with leukocytosis and multiple lymph-node swelling in the neck. Lymph-node biopsy revealed a myeloperoxidase-positive blastoma with cell-surface markers of myeloid and T-lymphoid lineages. Fluorescence in situ hybridization and the reverse transcription polymerase chain reaction detected a minor BCR breakpoint but failed to detect a major BCR breakpoint. By single-strand conformation polymorphism and direct sequencing, no alteration in the TP53 gene was found, and no additional chromosomal abnormalities other than Ph were identified. The present case suggests that p190 BCR/ABL is associated with the aggressive course of the disease.

Clinical course and therapy of chronic myelogenous leukemia with interferon-alpha and chemotherapy

This article begins with a review of the natural history of chronic myelogenous leukemia (CML), with an emphasis on prognostic features. Current standard therapy of CML with interferon-alpha based regimens, and interferon-alpha, in the context of allogenic stem cell transplantation is then discussed. Finally, some potentially effective novel agents including homoharringtonine, decitabine, ATRA, and topotecan are described.

Extramedullary blast crisis in chronic myeloid leukemia

Among 235 patients with CML we reviewed 91 patients with BC diagnosed between 1980 and 1995; 15 of the 91 (16%) developed extramedullary disease (EMD). The sites involved were the lymph nodes (13/15), CNS (1/15) and suborbital mass (1/15). The appearance of EMD was associated with chronic phase (CP) features in the bone marrow in 3/15 cases, with accelerated phase (AP) in 3/15 and with BC in 9/15. 11/15 (73%) cases of EMD were classified as myeloid (My-EMD) and 4/15 as lymphoid-type (Ly-EMD): three B-phenotype and one T-phenotype. All Ly-EMD cases were treated with vincristine, daunorubicin and prednisone and obtained complete remission (CR). Cases of My-EMD were treated with daunorubicin and cytosine arabinoside, of which only 1/11 achieved CR. We suggest that in EMD also, the type, lymphoid or myeloid, of BC has a bearing on treatment response and prognosis: Ly-EMD is more responsive to treatment and has longer survival than My-EMD.

Chronic myelogenous leukemia: a review

Chronic myelogenous leukemia (CML) is a chronic myeloproliferative disorder with an initially chronic course lasting for 3-5 years. It eventually transforms into accelerated and blastic phases, which are generally fatal. CML was one of the first diseases in which a specific chromosomal abnormality was identified, a t(9;22)(q34;q11) or Philadelphia chromosome. CML had been traditionally treated with conventional chemotherapy with hydroxyurea or busulfan. Although these agents can achieve hematologic remissions in most patients, no evidence of sustained disappearance of the chromosomal abnormality was evident. Interferon alpha (IFN-alpha) has been able to achieve hematologic and cytogenic remissions in a significant number of patients, and recent studies show a survival advantage for patients treated with IFN-alpha compared with those treated with conventional chemotherapy. The results of these studies are discussed, and the reasons for discordance among different investigators analyzed in this review. Allogeneic bone marrow transplantation (BMT) may be curative in some patients with CML. The benefits and limitations of this approach in the treatment of CML are also discussed and the results of different alternatives compared. Other alternatives of therapy, including newer chemotherapeutic agents, combinations of IFN-alpha with other agents, and autologous BMT, are presented. The availability of very sensitive techniques for detection of the Philadelphia chromosome at the molecular level has allowed the detection of minimal residual disease. The information available on these measurements is also analyzed. Finally, we discuss the alternatives for patients with accelerated and blastic phase CML, as well as the clinical characteristics and prognosis for patients with Philadelphia-chromosome-negative CML.

Usefulness of the rearrangement of the bcr/abl gene in extramedullary (lymph nodes) blast crisis diagnosed in chronic myeloid leukaemia

The introduction of molecular biological techniques in the study of chronic myeloid leukaemia (CML) allows us to show the bcr/abl gene rearrangement produced by the translocation between the c-abl proto-oncogene located in chromosome 9 and the bcr region located in chromosome 22, which constitutes the molecular alteration of Philadelphia chromosome in CML. We present the usefulness of the bcr/abl gene rearrangement study in the diagnosis of a blast crisis initially located in lymph nodes of a patient with CML. The DNA analysis allows demonstration that the lymph node neoplastic cells originate from the clone responsible for the CML, while obtaining metaphases from a lymph node for the cytogenetic study gives rise to enormous difficulties and is practically impossible if the problem is studied retrospectively based on frozen or fixed samples.

Non-lymphoid blast crisis of CML with rearrangement of immunoglobulin and T-cell receptor delta genes

We report a patient with chronic myeloid leukaemia (Philadelphia-positive with M-BCR rearrangement) in transformation whose blast cells had myelomonocytic morphology, absent terminal deoxynucleotidyl transferase expression and non-lymphoid cell surface markers (CD10-, CD19-, CD33+, CD14+, CD11+). Leukaemia cell DNA showed rearrangement of both immunoglobulin heavy chain and T-cell receptor delta genes. Such rearrangements may be a feature of a small proportion of patients with non-lymphoid transformation of CML as they are in a minority of cases of de novo acute non-lymphoblastic leukaemia.

Extramedullary blast crisis in a patient with Philadelphia chromosome-positive chronic myelogenous leukemia in complete cytogenetic remission

Treatment of Philadelphia (Ph) chromosome-positive chronic myelogenous leukemia (CML) with recombinant interferon-alpha (IFN-A) results in complete disappearance of the Ph chromosome in about 10% to 15% of patients in early chronic phase. This group has a long survival and very low incidence of blast crisis. The first known case is reported of extramedullary blastic transformation in a patient with medullary complete cytogenetic response (0% Ph-positive metaphases) to IFN-A. Four episodes of extramedullary blast crisis have occurred in this patient. The first three episodes were lymphoid by morphology and cytochemical stains. Molecular analysis confirmed breakpoint cluster region rearrangement. The most recent transformation was myeloid in nature and involved bone and pulmonary parenchyma. The patient is currently undergoing a second autologous transplantation with stored bone marrow that is Ph negative. The patient has survived more than 18 months since the first episode of blast crisis, and the bone marrow is normal.

Philadelphia chromosome-positive acute leukemia: morphologic and clinical correlations

Twenty-eight adult patients with Philadelphia chromosome positive (Ph+) acute leukemia were studied to determine if additional chromosomal changes were related to specific morphologic and clinical features. Twenty patients had chronic myeloid leukemia in blast crisis (CML-BC), three had Ph+ de novo acute nonlymphocytic leukemia (ANLL), and five had de novo acute lymphoblastic leukemia (ALL). Chromosomal abnormalities in addition to a single Ph were noted in 90% of patients with CML-BC and included a second Ph (five patients), +8 or duplication of part of 8q (five patients), dicentric isochromosome 17 (two patients), and +19 (two patients). Octaploidy with 4 Ph was seen in one patient with megakaryoblastic transformation. One of two patients with a progranulocytic blast crisis had a t(15;17) abnormality. Hypodiploidy was noted in 4 of 20 patients with CML-BC. Each of the four patients had prominent extramedullary manifestations of blast crisis. All had received intensive chemotherapy prior to the detection of hypodiploidy, and the cytogenetic findings were similar to those often seen in patients with therapy-related leukemia. An inv(3)(q21q26) was noted in two patients (one CML-BC, one de novo Ph+ ANLL), one of whom had hypolobulated micromegakaryocytes. Additional cytogenetic abnormalities in de novo Ph+ ANLL (especially +19) were similar to those in CML-BC. In contrast, the additional karyotypic changes in de novo Ph+ ALL (eg, +4, -7, -20, markers) were those commonly seen in ALL without a Ph and were generally different from those seen in CML-BC.

Clinical and prognostic features of patients with Philadelphia chromosome-positive chronic myelogenous leukemia and extramedullary disease

Twenty-four patients who developed extramedullary disease during the course of Philadelphia chromosome-positive chronic myelogenous leukemia are described. The most frequent sites of extramedullary disease were lymph nodes (54%), bone (37%), and skin and soft tissue (29%). The appearance of extramedullary disease was associated with a high incidence of other features of accelerated disease (37%) and with cytogenetic clonal evolution (62.5%). The median time from extramedullary disease to blastic crisis was 4 months, and the median survival was 5 months. At the time of analysis, 23 patients have died, 16 after evolving into blastic crisis, and 7 from progressive disease without satisfying the criteria of medullary blastic crisis. This study confirms the importance of extramedullary disease as a sign of poor prognosis in chronic myelogenous leukemia, and the need for alternate therapies when such an event develops.