Chronic myeloid leukaemia blast crisis with T-cell features

Philadelphia-chromosome-positive T-lymphoblastic leukemia: acute leukemia or chronic myelogenous leukemia blastic crisis

The Ph1 chromosome has rarely been reported in T-lineage acute lymphoblastic leukemia (T-ALL), and the clinical relevance of this translocation in T-ALL is currently unknown. In chronic myelogenous leukemia (CML) some data indicate derivation of T-cells from the leukemic clone and only a few cases of T-derived blastic crisis have been reported and quite often disputed. Particularly in cases identified initially in blastic crisis it may be difficult to distinguish those from Ph1-positive T-ALL. We herein report 2 patients who presented with a clinical picture of Ph1-positive T-ALL and who raised a differential diagnosis from T-cell blastic crisis of CML. We review the literature and suggest clinical and laboratory features that can help in the diagnosis. According to our literature review, 23 cases of Ph1-positive T-ALL and 44 cases of T-cell blastic crisis of CML, including ours, were reported. Some major differences between the two entities could help in establishing a diagnosis of Ph1-positive T-cell blastic crisis of CML vs. Ph1-positive T-ALL: Male sex and younger age was more predominant in T-ALL. While in most cases of CML blastic crisis there was a history of CML there was no such history in the T-ALL cases. Medullary involvement with lymphoblastic leukemia was present in all cases of T-ALL but only in about half of the cases of CML blastic crisis. None of the CML-blastic crisis cases tested by RT-PCR showed the minor breakpoint transcript, while 2 cases with T-ALL had the minor breakpoint transcript and 1 had both transcripts. Combined morphologic and FISH analysis can help to distinguish between the two entities and was applied in one of our cases. Although both entities carry a severe prognosis, differentiating between them might have clinical relevance, especially in the imatinib era.

Chronic myelogenous leukemia in T cell lymphoid blastic phase achieving durable complete cytogenetic and molecular remission with imatinib mesylate (STI571; Gleevec) therapy

BACKGROUND

A T cell lymphoid blastic phase of chronic myelogenous leukemia (CML) is a rare occurrence, with only a few reported cases worldwide. Standard therapy for such patients is undetermined. Imatinib mesylate, a Bcr-Abl tyrosine kinase inhibitor, has shown activity in CML.

METHODS

The authors report on a patient with CML and marrow as well as extramedullary nodal T cell lymphoid blastic phase who was treated with imatinib mesylate.

RESULTS

The patient achieved complete morphologic and cytogenetic remission within two months of therapy. Competitive quantitative polymerase chain reaction analysis of marrow cells was negative after 15 months. Response had lasted for 26+ months at the time of writing.

CONCLUSIONS

The current data suggest that imatinib mesylate may produce long-term event free survival in patients with T-cell lymphoid blastic phase CML. Its potential role alone or in combinations should be further explored in this condition.

Extramedullary T lymphoid blast crisis representing an additional translocation, t(6;8)(q25;q22) in a patient with Philadelphia-positive chronic myelogenous leukemia after allogeneic bone marrow transplantation

A patient with extramedullary crisis from chronic myelogenous leukemia after allogeneic bone marrow transplantation is reported. A pathological neck lymph node observed after transplantation revealed pre-T lymphoblastic phenotype, and the fluorescence in situ hybridization (FISH) analysis showed recipient type sex chromosomes and bcr/abl fusion gene. The cells represented an additional translocation, t(6;8)(q25;q22). No rearrangements of the T-cell receptor (TCR) beta, gamma or delta chain genes were observed. The absence of TCR rearrangement indicated the clonogenic involvement of pluripotent hematopoietic stem cells by Philadelphia chromosome. Bone marrow specimens at that time showed donor type sex chromosomes and no bcr/abl-positive cells by FISH.

Nodal T cell blast crisis in chronic myeloid leukemia

We report the case of a 54 year old male with an original diagnosis of chronic myeloid leukemia (CML) who developed a nodal T cell blast crisis (BC) while he was in a complete hematological remission (CR). We describe the clinical presentation and the histological, immunophenotypic and molecular characterization of the lymph node blast cells. Our case, together with other rare similar reports in the literature, argue that a T cell nodal blast crisis of CML resembles the presentation of a T-cell non-Hodgkin's lymphoma.

Detection of immunoglobulin heavy chain gene rearrangements by polymerase chain reaction analysis on lymph node imprints and fine-needle aspirate smears: a comparison of five different imprint preparations

Five different preparations of lymph node imprints from 39 patients were studied to determine which preparations are suitable for obtaining interpretable results with polymerase chain reaction (PCR)-based detection of immunoglobulin heavy chain gene rearrangements and whether there are significant discrepancies in the patterns obtained. The sensitivity and specificity of this test for the diagnosis of B-cell lymphoma were assessed. The five imprints were stained with May-Grünwald-Giemsa (MGG) and coverslipped, stained with MGG but not coverslipped, fixed in acetone only, air-dried only, or immunostained, respectively. The efficiency of the PCR was 0% for immunocytochemically stained slides, 87% for air-dried only and air-dried/MGG-stained/coverslipped slides, 95% for air-dried/MGG-stained/not coverslipped slides, and 100% for imprints that were air-dried/acetone-fixed. There was total agreement in results in 87% cases studied. Discrepancies never resulted in false-positive test results. The overall sensitivity was 50%, and specificity was 100%. Based on these results, we have devised guidelines for tissue treatment when only stained slides are available. In a prospective study with 19 fine-needle aspirate specimens, the efficiency of the PCR increased to 100%, and sensitivity improved to 81%.

Ex vivo fine-needle aspiration cytology and flow cytometric phenotyping in the diagnosis of lymphoproliferative disorders: a proposed algorithm for maximum resource utilization

Surface marker characterization of lymphoproliferative disorders is an essential component in the diagnostic work-up of these lesions. Immunohistochemical surface marker analysis (SMA) is somewhat costly, fixation-dependent, and difficult to objectively quantitate. Two-color flow cytometric (TCFCM) SMA allows for more quantitative dual marker analysis of a wide range of surface antigens, and is less expensive. Ex vivo fine-needle aspiration (xvFNA) has been reliably used for FCM DNA analysis. The procedure has also been used to harvest tumor cells for xenotransplantation. In this study, we attempted to test the reliability of material obtained by xvFNA for SMA. We also designed an algorithm initiated by cytological assessment of the xvFNA smears in order to tailor the panel of antibodies required for TCFCM SMA of the aspirates. We performed 20 xvFNAs on freshly resected specimens from 19 patients with suspected lymphoproliferative disorders. The specimens included 12 lymph node biopsies, seven splenectomies, and one breast biopsy. There were 10 male and nine female patients with a median age of 58 yr. The aspirate cell suspensions were examined by FCM within 24 hr of harvesting. The number of markers used ranged from four to 14 with an average of eight. The diagnoses included non-Hodgkin's lymphoma (n = 5), lymphocytic leukemia (n = 5), reactive lymphoid hyperplasia (n = 8), and Hodgkin's disease (n = 1). Combining cytological assessment of the xvFNA smears and TCFCM SMA, the diagnosis was reached prior to histopathologic examination in 17 cases (90%). The two remaining cases showed a reactive pattern on cytology and a polyclonal FCM SMA profile, and the diagnosis of sarcoidosis and toxoplasmosis was made on histological examination. Our study suggests that xvFNA provides adequate material for TCFCM SMA. An algorithm combining xvFNA cytology, FCM SMA, and histological examination is appropriate for the diagnosis of lymphoproliferative disorders in most instances with maximal resource utilization and minimal expense.

Immunophenotype and ultrastructural studies in blast crisis of chronic myeloid leukemia

Thirty-four patients with chronic myeloid leukemia in blast crisis (CML-BC) were evaluated for lineage differentiation with immunological markers and the presence of ultrastructural peroxidase. Eighteen (52.9%) were found to have myeloid blast crisis. Cytochemically, myeloperoxidase (MPO) could be detected only in six patients on light microscopy while in the remaining 12 patients, myeloid differentiation was confirmed only by demonstration of MPO either at ultrastructural level or by the reactivity with anti myeloperoxidase (anti MPO) antibody. Six (17.6%) had lymphoid blast crisis as identified by lymphoid specific markers (CD19; CD10; CD7; CD4) along with the absence of myeloid markers. Heterogenous blast cell populations with mixed lineage differentiation were seen in 4 (11.7%) patients. These cases showed both lymphoid (CD19, CD10) and myeloid (anti MPO and ultrastructural MPO) characteristics. A single case of megakaryoblastic blast crisis was identified with positivity for CD41 and CD42 along with the presence of platelet peroxidase at the ultrastructural level. Five cases (14%) of CML blast crisis remained unclassifiable. These results suggest that blast crisis in CML show an arrest of differentiation at an early stage when compared to de novo acute leukemias. This is particularly evident from the fact that MPO could only be demonstrated ultrastructurally or with anti MPO antibody in the majority of patients with myeloid differentiation. It is expected that utilisation of molecular studies including immunoglobulin and T-cell receptor gene rearrangement and m-RNA expression for myeloperoxidase will provide a better insight into the level of differentiation for the presently unclassifiable cases of CML-blast crisis.

Emergence of myeloid stem cell line from T-lymphoid blastic phase of chronic myeloid leukemia in culture

A new cell line designated JA-CML was derived from the peripheral blood of a patient with blastic phase CML. Sequential evolution of phenotypic and genetic markers was demonstrated during adaptation from primary to continuous culture in vitro. In the primary sample the majority of blast cells displayed the early T-cell markers, CD7, HLA-DR, and TdT, but were negative for the common ALL antigen (CALLA), CD4 and CD8. Simultaneously, unstimulated metaphase cells showed great karyotypic variation with a range of 43-46 chromosomes per cell. Clonal changes included the Ph chromosome t(9;22), loss of the Y and gain of several altered chromosomes. The cells grew slowly in suspension during the first 10 weeks of culture. During that time, cells still expressed the CD7 and HLA-DR antigens. Karyotypic analysis at ten weeks showed a pattern of 46,X,-Y,t(9;22),+8 in more than 90% of metaphases with disappearance of all other abnormal chromosomes noted in the original sample. A tetraploid subline exhibiting duplication of most chromosomes, including the Ph, comprised the remaining metaphases. Upon further cultivation in vitro, the cells transformed spontaneously over a period of several weeks, from T-lymphoid into myeloid cells. Expression of CD7 was lost, but reactivities with monoclonal antibodies to CD34, CD33 and CD13 were newly acquired. The karyotype was hypertriploid and all cells carried two copies of t(9;22) and lacked normal copies of No. 9 or Y. The cells have since maintained stable cytogenetic and phenotypic profiles. Molecular rearrangement of the breakpoint cluster region was identified in the primary blasts and the established line and T-cell receptor gene rearrangements were not found. These observations suggest that the leukemic blast arose from primitive stem cells, not irreversibly committed T cells, and that these stem cells retained the capacity to differentiate along the myeloid pathway.

Immune markers in hematologic malignancies

The precise delineation of biologic traits that distinguish normal hematopoietic cells from their malignant counterparts is of fundamental importance in understanding all aspects of hematologic malignancies. An increasingly sophisticated technologic battery has been utilized to dissect out these differences--primarily utilization of monoclonal antibodies, by immunoperoxidase, immunoalkaline phosphatase and flow cytometric techniques. An even more basic understanding of normal and malignant hematopoietic cells has begun to evolve as molecular biology begins to unravel gene misprogramming by Southern and Northern blot analysis and the polymerase chain reaction. These techniques not only help distinguish a normal cell from a malignant one, but characterize the malignant clone as B-lymphoid, T-lymphoid or myeloid and allow further subcategorization within these broad lineages. These distinctions are vital to the entire spectrum of basic and clinical research involving hematologic malignancies and are assuming an increasingly important role in their diagnosis, prognosis and treatment.

Extramedullary blast crisis in chronic myelogenous leukemia. Demonstration of T-cell lineage and Philadelphia chromosome in a paraspinal tumor

A case of chronic myelogenous leukemia (CML) with penetrance of the Ph1 molecular alteration into the T-cell lineage of a paraspinal tumor is reported. The T-cell nature of the paraspinal tumor was documented by immunochemical study and genotyping. The Philadelphia chromosome was also detected by genotyping in the same tumor cell population. To the authors' knowledge, this is the first case of extramedullary T-cell blast crisis in CML demonstrated in an extranodal tumor. The clinical significance of detecting extramedullary blast crisis, and the theories for the scarcity of T-cell transformation in CML are discussed.

T-lymphoid blast crisis in chronic myeloid leukemia

Chronic myeloid leukemia (CML) is considered to be a pleuripotential stem cell disorder with the capacity to differentiate into myeloid, erythroid, megakaryocytic, and lymphoid cell lines. Consequently, blast crisis (BC) involving each of the above lineages has been well described. Among lymphoblastic crises, differentiation frequently occurs along B-cell lineage. We report four patients of CML who terminated in T-cell extramedullary BC in lymph nodes after a variable duration of chronic phase. The T-lineage was established by characteristic cytochemical staining and reactivity with a panel of anti-T-cell monoclonal antibodies. All four cases were Philadelphia (Ph) chromosome positive and demonstrated the Ph chromosome and associated anomalies (extra Ph, +19) in the lymph nodes. Our data adds to the growing evidence that CML is a disorder of the common stem cell from which T, B, and myeloid precursors originate.

Natural killer lymphocyte blast crisis of chronic myelogenous leukemia

We describe for the first time a case report documenting a chronic myelogenous leukemia (CML) patient who developed a blast crisis of natural killer (NK) lymphocytes. Many of the blasts exhibited large granular lymphocytic (LGL) morphology. Single parameter immunophenotyping results determined that the granulated as well as the agranulated blast cells were NK lymphocytes (CD45, NKH1, CD2, LEU 17, and CD16 positive; CD3, CD8, and LEU 7 negative). Dual parameter flow cytometric testing also determined that some of the blasts expressed the CD11b and CD11c markers as reported for some types of NK lymphocytes. Approximately 10% of the cells were in the S phase of the cell cycle as determined by a modified Vindelov DNA content analysis test and may theoretically reflect some of those cells expressing CD11b and CD11c. The cells did not express in vitro NK lymphocyte functional activity against a K562 target and therefore similar to other reported cases of presumably immature NK lymphocytic leukemias. The NK lymphocyte blast crisis was successfully treated with vincristine and prednisone. The patient's disease eventually relapsed and transformed to a progenitor stem cell before she died (CD45, 13, CD38, and CD34 positive). The flow cytometric immunophenotyping results contributed significantly as an important adjunct in determining the appropriate diagnosis, helping to select the type of therapy, and monitoring the patient with this unusual type of blast crisis.

Laboratory and clinical applications of monoclonal antibodies for leukemias and non-Hodgkin's lymphomas

Important insights into leukocyte differentiation and the cellular origins of leukemia and lymphoma have been gained through the use of monoclonal antibodies that define cell surface antigens and molecular probes that identify immunoglobulin and T-cell receptor genes. Results of these studies have been combined with markers such as surface membrane and cytoplasmic immunoglobulin on B lymphocytes, sheep erythrocyte receptors on T lymphocytes, and cytochemical stains. After using all of the aforementioned markers, it is now clear that acute lymphoblastic leukemia (ALL) is heterogeneous. Furthermore, monoclonal antibodies that identify B cells, such as the anti-CD20 and anti-CD19 antibodies in combination with studies of immunoglobulin gene rearrangement, have demonstrated that virtually all cases of non-T-ALL are malignancies of B-cell origin. At least six distinct subgroups of non-T-ALL can now be identified. T-ALL is subdivided by the anti-CD7, anti-CD5, and antibodies that separate T lymphocytes subsets into three primary subgroups. Monoclonal antibodies are also useful in the subclassification of non-Hodgkin's lymphoma, and certain distinct markers can be correlated with morphological classification. Although monoclonal antibodies are useful in distinguishing acute myeloid from acute lymphoid leukemias, they have less certain utility in the subclassification of acute myelogenous leukemia (AML). Attempts to subclassify AML by differentiation-associated antigens rather than by the French-American-British (FAB) classification are underway in order to document the potential prognostic utility of surface markers. Therapeutic trials using monoclonal antibodies in leukemia and lymphoma have been reported. Intravenous infusion of unlabeled antibodies is the most widely used method; transient responses have been demonstrated. Antibodies conjugated to radionuclides have been quite successful in localizing tumors of less than 1 cm in some studies. Therapy trials with antibodies conjugated to isotopes, toxins, and drugs have shown promise. Purging of autologous bone marrow with monoclonal antibodies and complement in vitro has been used in ALL and non-Hodgkin's lymphoma; preliminary data suggest that this approach may be an effective therapy and may circumvent many of the obstacles and toxicities associated with in vivo monoclonal antibody infusion.

Multilineage cell involvement in Ph1-negative, bcr-negative chronic myeloid leukemia

We report a case of Ph1-negative, bcr-negative CML-BC, in which the primary leukemic cells displayed T-related antigens (CD7, CD4) in addition to HLA-DR and CD25 determinants. No B-lymphoid, myeloid and megakaryoblastic surface antigens were detected. In spite of this phenotype, DNA analysis revealed a germ-line configuration of the T-cell receptor beta chain gene region. Moreover, in-vitro culture studies demonstrated a proliferative response of the blast cell population to natural and recombinant myeloid-related factors, while no proliferative signal was observed in the presence of IL-2. The myeloid lineage was further demonstrated by the expression of myeloid-associated antigens on cultured blast cells, which still retained the CD7 antigen. Finally, cytogenetic analysis revealed a monosomy 7 which is usually associated with a stem cell leukemia. These results support the hypothesis that Ph1-negative, bcr-negative CML is characterized by the involvement of a multipotent stem cell capable of multilineage expression and indicate that differentiative and proliferative assays provide a further tool towards a more precise recognition of hematological disorders of uncertain origin.

Chronic granulocytic leukemia: the devastating consequences of genetic instability

Recent advances in the pathogenesis and treatment of chronic granulocytic leukemia (CGL) are reviewed. Three major phases of CGL are recognizable: the presymptomatic phase, the chronic phase, and the metamorphosis. The molecular dissection of the Philadelphia chromosome has revealed that this translocation activates the c-abl oncogene by fusion with another gene called bcr whose function is as yet unknown. Although almost all patients with CGL still succumb within 10 years of diagnosis, alpha-interferon and allogeneic bone marrow transplantation represent promising newer therapeutic developments. In particular, marrow transplantation appears to have curative potential in CGL.

T-cell involvement in benign phase chronic myelogenous leukemia

T cells from the peripheral blood of patients with chronic myeloid leukemia (CML) were cultured with phytohemagglutinin and T-cell growth factor (TCGF) in agar culture. These T-cell colonies were pooled and expanded further in liquid culture with TCGF and then simultaneously analysed for the E-rosette receptor with the monoclonal antibody OKT11 and for the presence of the Philadelphia (Ph1) chromosome. OKT11 analysis showed these populations to be composed 99.5% or more of T cells. In four of the seven patients the T-cell suspension showed 7/50 (14%), 3/36 (8%), 2/34 (6%), and 4/44 (9%) Ph1 metaphases. Furthermore, Ph1 metaphases were demonstrated in T-cell cultures in two patients when bone marrow metaphases simultaneously showed 90 and 100% Ph1 negative metaphases secondary to human leukocyte interferon therapy or combination chemotherapy. A minority of T cells in benign phase CML have the Ph1 abnormality despite reduced number of Ph1 metaphases in bone marrow from therapy.

Extramedullary presentation of the blast crisis of chronic myelogenous leukaemia

We report the clinical histories and a multiparameter pathological study of the extramedullary lesions of seven patients with chronic myelogenous leukaemia in whom the initial clinical presentation of blast crisis (BC) was in an extramedullary site (lymph nodes in six, mandibular mass in one). Bone marrow BC was demonstrated simultaneously or within a few months in four patients. Three patients received chemotherapy only, four underwent bone marrow transplant. Six patients died within 1 year from diagnosis of extramedullary BC, one is alive without disease. The longest survivals (12+, 12, 11 months) were those of patients who never developed bone marrow BC and were recipients of bone marrow transplant. Studies of extramedullary disease included: histology; histochemistry for chloracetate esterase (CAE) and lysozyme; assays for TdT; electron microscopy; immunofluorescence for Fc-receptors, immunoglobulins and lymphoid and myeloid antigens by a panel of monoclonal antibodies; and cytogenetics. Three cases were classified as myeloid BC based on histochemistry and/or ultrastructure and immunology (OKM1+, MCS2+, IG10+); two as lymphoid BC (CAE-, lysozyme-, TdT+), one of them expressing a T-cell phenotype. Cytogenetic analysis of extramedullary lesions and simultaneous or subsequent bone marrows demonstrated identical karyotypes in three patients and significantly different karyotypes in one.

Early T-cell features in blast crisis of Ph1-positive chronic myeloid leukaemia

A patient with Ph1-positive chronic myeloid leukaemia (CML) presented in extramedullary blast crisis. Whereas the peripheral blood and bone marrow features were consistent with the chronic phase of CML, study of the enlarged lymph nodes demonstrated massive replacement by Ph1-positive blast cells of lymphoblastic morphology. Such blast cells showed diffuse acid phosphatase positivity, were positive for TdT, and had an enzyme pattern (adenosin-deaminase, purine-nucleosidephosphorilase and lactate-dehydrogenase) typical of immature T-cells. To further characterize the phenotype of the blast cells, they were analyzed for surface markers using a panel of monoclonal antibodies selected to identify differentiation antigens of T cells, B cells and myeloid cells. The results of the latter analysis were consistent with an early T-cell origin of the blast cells, since they were positive for TdT, CRIS1 (T1), E rosettes and OKT10, and were negative for OKT3, Leu3 and OKT8. These features demonstrate that T-cell markers may also be expressed in blast crisis of CML and provide evidence that T-cells may share a common stem cell with myeloid and B-cells in CML.

Biphenotypic leukaemia: a case of mixed T lymphoblastic and myeloblastic leukaemia

A case of mixed acute leukaemia with T lymphoblastic, myeloblastic, and monocytic components is described. The use of immunological markers, ultrastructural morphology, cytochemistry, immunochemistry, and combined techniques, simultaneously detecting two markers in individual cells, made it possible to define the different blast cell populations.

Lymphoid crisis with T-cell phenotypes in a patient with Philadelphia chromosome negative chronic myeloid leukaemia

A case of Philadelphia (Ph1) chromosome negative chronic myeloid leukaemia (CML) developed lymphoid crisis. Immunological marker studies disclosed that the lymphoid cells were sheep erythrocyte-rosetting-, Leu-1+, Leu-5+, OKT-4+, OKT-8+, common ALL antigen-, HLA-DR-, cytoplasmic and surface immunoglobulin-, MAS 036C(antithymocyte)+ (after in vitro culture) and terminal deoxynucleotidyl transferase-, indicating T-cell phenotypes, probably of common thymocytes. Cytochemical staining also demonstrated immature T-cell characters: dot-positivity for acid phosphatase and beta-glucuronidase, and negative for acid alpha-naphthyl acetate esterase. All bone marrow metaphases exhibited normal karyotypes. Our observation suggests that the neoplastic features of a common stem cell for myeloid and lymphoid cell lines are very similar in Ph1 positive and negative CMLs, and that the stem cell can differentiate towards T-lineage.

E rosette-positive agar colonies containing the Philadelphia chromosome in chronic myeloid leukaemia

In an attempt to document possible T-cell involvement in chronic myeloid leukaemia, E rosette-positive colonies (ERPC) were grown in agar culture using a T-cell-conditioned medium. Colonies were grown from whole mononuclear cells (WMN), nonadherent E rosette-positive (NAT+) and nonadherent E rosette-negative (NAT-) cells. Cells collected from the colonies after 10 d in culture were 99-100% E rosette-positive. 8 metaphases were obtained from both NAT+ and NAT- ERPCs. In NAT- ERPCs, 5 out of 8 metaphases were positive for the Philadelphia (Ph1) chromosome as compared to 1 Ph1 positive out of 8 metaphases in the NAT+ ERPCs. These results suggest that, at least in this particular patient we studied, a subpopulation of E rosette-positive cells derived from the NAT- cell fraction express the Ph1 chromosome.

Characterization of extramedullary tumors in a case of Ph-positive chronic myelogenous leukemia: possible involvement of immature T lymphocytes

A 42-year-old male with chronic myelogenous leukemia (CML) developed acute transformation associated with subcutaneous tumors. Histopathologic examinations of the tumors were done on two occasions; the first study revealed reticulum cell sarcoma-like features, and the second suggested a blastoma. Chromosomal analysis showed that the cells of the tumors originated from the CML clone. The cells had a negative reaction for myeloperoxidase by electron microscopy. Furthermore, biochemical and surface marker studies revealed that the tumor cells contained a significant terminal transferase activity. However, they did not express E- or EAC-rosette receptors, Ia-like antigens, or common ALL antigens.

Ph1-positive and Ph1-negative abnormal cell lines in a child with lymphoblastic lymphoma

A 7-year-old Japanese boy with Ph1-positive-lymphoblastic lymphoma is described. The diagnosis was based on biopsied tonsils which were enlarged at the time of admission. On the eighth day after admission an enlarged mediastinal mass was detected on a chest X-ray film. The lymphoblasts which appeared in the peripheral blood and bone marrow proved to be T-cells. Chromosome studies on the bone marrow cells revealed two abnormal cell lines; one had a 7;11 translocation and the other a 7;11 translocation and a 9;22 translocation, forming the Ph1-chromosome. The latter line with the Ph1-chromosome was considered to have been derived from the former line without the Ph1. Our findings show that the Ph1-chromosome may be a secondary change in the course of karyotypic evolution.

Ph1 positive blast crisis of chronic myeloid leukaemia exhibiting features characteristic of early T blasts

Leukaemic cells from a patient in the blast crisis of chronic myeloid leukaemia were subjected to a surface marker analysis using a panel of monoclonal antibodies recognizing differentiation antigens of myeloid (MY7, MY906, VIM D5, M phi P9), erythroid (VIE G4), megakaryocyte (AN51), T-lymphoid (WT1, 10.2, OKT3, OKT4, OKT6, OKT8, OKT11A) and B-lymphoid cells (B1, B2, Y29/55), common ALL-antigen (VILA1), non-lineage-restricted antigens (OKT9, OKT10), monomorphic HLA-DR determinants (7.2) as well as TdT. When the patient entered his first blast crisis, his blasts expressed a phenotype corresponding to an immature myeloid cell (7.2+, MY7+, My906+, VIM D5-). Ph1-chromosome-positive blasts from this patient's first relapse had completely changed their surface marker characteristics: they had become TdT-positive and exhibited surface features characteristic of early T blasts (WT1+, 10.2+, OKT9+, OKT10+, 7.2-, OKT6-). Together, these features provide evidence that myeloid cells may share a common precursor with T cells.