Immunophenotypic analysis of hematogones (B-lymphocyte precursors) in 662 consecutive bone marrow specimens by 4-color flow cytometry

Bone marrow hematogones (B-lymphocyte precursors) may cause problems in diagnosis because of their morphologic and immunophenotypic similarities to neoplastic lymphoblasts. The purposes of this prospective, multiparametric flow cytometry study were to quantify hematogones across age groups and a spectrum of clinical conditions, to identify factors that affect the relative quantity of hematogones, and to compare their immunophenotype with that of neoplastic lymphoblasts. A total of 662 consecutive marrow specimens were analyzed for hematogones using one of two 4-color antibody combinations; hematogones were identified in 528 (79.8%). There was a significant decline in hematogones with increasing age (P <.001), but a broad range was found at all ages and many adults had a relatively high number. Specimens processed by density gradient had a higher mean percent hematogones than those processed by erythrocyte lysis (P <.001). There was a direct decline in hematogones with increasing marrow involvement with neoplastic cells. A total of 8% of the 662 specimens contained 5% or more hematogones: 24.6% of specimens from patients aged less than 16 years and 6.3% from those 16 and older (P <.000 01). Increased hematogones were observed most often in patients with lymphoma, marrow regenerative states, immune cytopenias, and acquired immunodeficiency syndrome. Hematogones always exhibited a typical complex spectrum of antigen expression that defines the normal antigenic evolution of B-cell precursors and lacked aberrant expression. In contrast, lymphoblasts in 49 cases of precursor B-ALL showed maturation arrest and exhibited 1 to 11 immunophenotypic aberrancies. Four-color flow cytometry with optimal combinations of antibodies consistently distinguishes between hematogones and neoplastic lymphoblasts.

Immunophenotypic analysis of peripheral T-cell neoplasms. A multiparameter flow cytometric approach

We retrospectively reviewed multiparameter flow cytometric analyses in 50 peripheral T-cell neoplasms (PTCNs). Results were interpreted within the context of a large cohort of nonneoplastic T-cell populations. All PTCN diagnoses were confirmed with morphologic and/or molecular analysis. Aberrant populations were defined as discrete immunophenotypic clusters exhibiting loss of or increased or diminished expression of T-cell antigens relative to internal immunophenotypically normal T-cell populations. An antigenic pattern was considered abnormal if it exceeded ranges for T-cell subsets in specific anatomic sites or was not normally encountered. Forty-six of 50 and 41 of 50 demonstrated 1 or more and 2 or more aberrations, respectively. The most common abnormally expressed antigen was CD3, followed by CD7, CD5, and CD2. Except for CD7, abnormally dim or bright antigen expression was more common than deletion. Only 3 cases were abnormal solely based on expansion of an otherwise immunophenotypically normal population; the remainder had patterns of antigen expression not seen in nonneoplastic populations. These data indicate that most PTCNs are aberrant by multiparameter flow analysis. However, results must be interpreted within the context of thorough knowledge of the immunophenotypic spectrum of nonneoplastic T cells.

Transient myeloproliferative disorder and acute myeloid leukemia in Down syndrome. An immunophenotypic analysis

Immunophenotypic analysis of transient myeloproliferative disorder (TMD) and acute myeloid leukemia (AML) using multiparameter flow cytometry might provide insight into their relationship. We retrospectively analyzed the expression of multiple lymphoid, myelomonocytic, and megakaryocytic antigens on blast proliferations in 18 patients with Down syndrome (DS; AML, 9; TMD, 9). The AMLs and TMDs shared several immunophenotypic characteristics. Blasts in all expressed CD45, CD38, and CD33; most AMLs and all TMDs were CD36+; and the majority expressed CD41 and CD61, suggesting megakaryocytic differentiation. The majority of cases were CD34+, CD14-, and CD64-. There was aberrant expression of the T-cell-associated antigen CD7 in most AMLs and TMDs. CD56 was expressed aberrantly in 5 AMLs and 7 TMDs. The major difference between the disorders was the pattern of expression of myeloid markers CD11b and CD13; each was expressed in 8 AMLs but only 2 TMDs. Blasts were HLA-DR-positive in 3 AMLs vs 7 TMDs. Blasts in TMD and AML in DS have a characteristic immunophenotype distinct from AML in other settings. The immunophenotypic similarities suggest a biologic relationship between the disorders; however, distinct immunophenotypic differences also were observed.

Clinicopathologic analysis of CD10+ and CD10- diffuse large B-cell lymphoma. Identification of a high-risk subset with coexpression of CD10 and bcl-2

We analyzed 53 cases of diffuse large B-cell lymphoma (DLBCL) to determine whether expression of CD10 is a relevant biologic parameter. Tumor morphologic features were assessed semiquantitatively. Bcl-2 protein expression was studied by immunohistochemical analysis. The presence or absence of CD10 by flow cytometry was correlated with clinical and pathologic characteristics. CD10+ (23 cases) and CD10- (30 cases) DLBCLs were indistinguishable based on age, sex, extranodal presentation, B symptoms, clinical stage, morphologic features, or bcl-2 expression. However, cases with a CD10+ phenotype showed a significantly lower rate of complete remission. Cases expressing bcl-2 showed trends toward a lower rate of complete remission and poorer overall survival. Examination of CD10 and bcl-2 interaction revealed that the prognostic effects for both of these antigens were due to a subset of CD10+ bcl-2-positive cases. Compared with cases expressing one or neither of these markers, patients with dual-positive tumors had a poorer complete response rate to initial therapy and strikingly worse overall survival. While CD10+ and CD10- DLBCLs are similar with regard to a variety of clinical and pathologic features, CD10 and bcl-2 coexpressing tumors are an extremely high-risk subset based on response to therapy and overall survival.

Precursor B-cell lymphoblastic lymphoma. A study of nine cases lacking blood and bone marrow involvement and review of the literature

We describe 9 cases of precursor B-cell lymphoblastic lymphoma (LYL) without evidence of marrow or blood involvement. Four patients had superficial nodal disease, 2 cutaneous involvement, and 1 each ovarian, retroperitoneal, or tonsillar primary tumor. Six patients had limited disease; 3 patients were stage III. Immunophenotyping revealed a terminal deoxynucleotidyl transferase (TdT)-positive, immature B-cell population with variable expression of CD10, CD20, and CD45. All patients are in complete clinical remission (median follow-up, 14 months). A literature review yielded 105 patients with a diagnosis of precursor B-cell LYL based on less than 25% marrow involvement. Of these, 64% were younger than 18 years. Skin, lymph nodes, and bone were the most common sites of disease. Mediastinal involvement was uncommon. TdT, CD19, CD79a, CD10, and HLA-DR were the most frequently expressed antigens, while CD45 and CD20 were expressed in only two thirds of the cases. Cytogenetic analysis showed additional 21q material as a recurring karyotypic abnormality. At a median follow-up of 26 months, 74% of patients were alive; the median survival was 19 months for patients dying of disease. Comparison with precursor B-cell acute lymphoblastic leukemia showed several overlapping features, although distinct differences were identified.

Large cell lymphoma transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma. A flow cytometric analysis of seven cases

We studied 7 cases of large cell transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) immunophenotyped by multiparameter flow cytometry. The 6 women and 1 man ranged in age from 45 to 91 years. All had previous or concurrent evidence of CLL/SLL. Morphologic features and sites of involvement of the diffuse large B-cell lymphoma (DLBCL) were heterogeneous; 2 cases had paraimmunoblastic morphologic features. Six DLBCLs had an immunophenotype consistent with CLL: CD19+, CD5+, CD23+, and FMC7 negative (3 cases) or very dim (2 cases); 1 case was not studied for FMC7. CD20 was dim in 3 of these, moderate to bright in 2, and variable in 1. Surface immunoglobulin was dim in 2 cases and moderate or bright in 4. Five of 6 expressed CD38. Comparison with the immunophenotypes of the previous or coexistent CLL/SLL (4 of 6 cases) revealed minor modulations in antigen expression but no major alterations. The seventh DLBCL lacked CD5 expression, but otherwise had immunophenotypic features similar to CLL. These findings indicate that DLBCL arising in CLL/SLL tends to retain a CLL immunophenotype, in contrast with de novo CD5+ large cell lymphomas that uncommonly express such a phenotype.

Prognostic significance of tumour-infiltrating T lymphocytes and T-cell subsets in de novo diffuse large B-cell lymphoma: a multiparameter flow cytometry study

Tumour-infiltrating T lymphocytes (TIL-T) have been implicated in playing a role in controlling tumour growth. We evaluated TIL-T in 55 cases of de novo diffuse large B-cell lymphoma (DLBCL) using three- or four-colour flow cytometric immunophenotyping (FCI). The percentage of TIL-T varied from 3% to 72% of total viable cellular events (mean 32 +/- 20%). The CD4:CD8 ratio varied from 0.17 to 13 (mean 2.3 +/- 2.2). Cases with >/= 20% T cells and those with CD4:CD8 ratios > or = 2.0 showed a significantly better overall survival (P = 0.017 and P = 0.034 respectively). These findings were independent of clinical stage at diagnosis. The T-cell percentage and CD4:CD8 ratio were moderately correlated (Spearman correlation coefficient = 0.47, P = 0.001) and multivariate analysis revealed that the association of the two factors with prognosis was mutually dependent. The T cells in 23 cases were studied for CD45RO. The mean percentage of total T cells expressing CD45RO was 86 +/- 10%. There was a trend towards better survival for those patients with a higher percentage of CD45RO+ T cells (P = 0.06). These results suggest that TIL-T, particularly CD4+ T cells, may play a role in the control of DLBCL, and measurement of T-cell percentage and T-cell subsets using FCI may be useful in predicting the clinical behaviour of DLBCL.

De novo CD5+ diffuse large B-cell lymphomas. A heterogeneous group containing an unusual form of splenic lymphoma

We reviewed our institutional experience with de novo CD5+, large B-cell lymphomas to determine whether they represent a distinct entity and are related to CD5+ small B-cell disorders. We identified 13 cases with multiparameter flow cytometry over a period of 58 months (5% of large B-cell lymphomas) in 7 females and 6 males. Three groups were identified. Group 1 (2 cases) had diffuse splenic red pulp involvement with a distinctive cordal pattern of infiltration, no other clinical evidence of mass disease, microscopic disseminated disease on further workup, and an identical immunoglobulin-negative immunophenotype. Group 2 cases (7 cases) were clinically and morphologically heterogeneous and had an immunophenotype resembling mantle cell lymphoma (FMC7-positive, CD23-). Group 3 (4 cases) had miscellaneous immunophenotypes, including one closely resembling chronic lymphocytic leukemia. Cyclin D1 was positive in only 1 of 10 evaluable cases (group 2). We conclude that CD5+ diffuse large B-cell lymphomas are heterogeneous; most cases do not seem to be related to chronic lymphocytic leukemia or mantle cell lymphoma. However, we identified a subgroup of primary splenic CD5+ large B-cell lymphoma with diffuse red pulp involvement and believe this may represent a distinct clinicopathologic entity.

Multifaceted approach to the diagnosis and classification of acute leukemias

Until recently, the diagnosis and classification of acute myeloid (AML) and acute lymphoblastic (ALL) leukemias was based almost exclusively on well-defined morphologic criteria and cytochemical stains. Although most cases can be diagnosed by these methods, there is only modest correlation between morphologic categories and treatment responsiveness and prognosis. The expansion of therapeutic options and improvement in remission induction and disease-free survival for both AML and ALL have stimulated emphasis on defining good and poor treatment response groups. This is most effectively accomplished by a multifaceted approach to diagnosis and classification using immunophenotyping, cytogenetics, and molecular analysis in addition to the traditional methods. Immunophenotyping is important in characterizing morphologically poorly differentiated acute leukemias and in defining prognostic categories of ALL. Cytogenetic and molecular studies provide important prognostic information and are becoming vitally important in determining the appropriate treatment protocol. With optimal application of these techniques in the diagnosis of acute leukemias, treatment strategies can be more specifically directed and new therapeutic approaches can be evaluated more effectively.

Unusual bone marrow manifestations of parvovirus B19 infection in immunocompromised patients

Parvovirus B19 is responsible for a spectrum of disease in humans. The usual bone marrow findings in acute parvovirus infections are marked erythroid hypoplasia and occasional giant erythroblasts. Intranuclear inclusions in developing erythroid precursors are rarely described in children or adults with parvovirus infection, although abundant intranuclear inclusions are commonly observed in the placenta and other tissues in infected fetuses. In this study, 8 patients are reported in whom the first evidence of parvovirus infection was the recognition of numerous intranuclear inclusions in erythroid precursors on bone marrow biopsy sections. Six of the 8 patients had documented immunodeficiencies; 4 had acquired immune deficiency syndrome (AIDS), and 2 were on chemotherapy. Five of 7 patients were negative for immunoglobulin G (IgG) antiparvovirus antibodies, including all 4 with AIDS. Unlike the typical pattern in parvovirus infection, the bone marrow was hypercellular in most of the patients, and erythroid precursors were usually increased with the entire spectrum of normoblast maturation represented; abundant intranuclear inclusions were observed similar to the finding in fetuses. The inclusions were variably eosinophilic and compressed the chromatin against the nuclear membrane. In situ hybridization showed parvovirus B19 DNA in numerous erythroid precursors in all cases. The findings of erythroid maturation and abundant viral inclusions in these immunocompromised patients is consistent with the hypothesis that failure to produce effective IgG parvovirus neutralizing antibodies may lead to persistent infection through viral tolerance that allows erythroid development of infected cells past the pronormoblast stage. Identification of parvovirus inclusions in marrow biopsies and subsequent confirmation of infection by in situ hybridization can be important in the assessment of anemia in immunodeficient patients because serological studies for parvovirus B19 are frequently negative.

Cytoplasmic inclusions in leukocytes. An unusual manifestation of cryoglobulinemia

Cryoglobulins are circulating immunoglobulins characterized by reversible, cold-induced precipitation. A variety of laboratory abnormalities, including hypocomplementemia, elevated erythrocyte sedimentation rate, rheumatoid factor activity, pseudoleukocytosis, and pseudothrombocytosis, are associated with cryoglobulinemia. Extracellular, faintly basophilic, amorphous deposits of cryoglobulins occasionally have been described in blood smears. In the present study, smears prepared from blood collected at room temperature from 6 patients with cryoglobulinemia exhibited neutrophil and, occasionally, monocyte inclusions containing clear, light pink, or faintly basophilic amorphous material. The inclusions were absent in smears from blood collected and maintained at 37 degrees C. Ultrastructural examination revealed that the material within the leukocyte inclusions was consistent with phagocytosed immunoglobulins. The identification of characteristic cytoplasmic inclusions in leukocytes may be an important clue in the early recognition of cryoglobulinemia.

Primary body cavity-based AIDS-related lymphomas

Five patients with advanced AIDS developed a unique type of high grade primary body cavity-based non-Hodgkin's lymphoma (NHL). The lymphomas were exclusively in serous effusions with no detectable mass disease in the body cavities and no lymphadenopathy or organomegaly. All of the lymphomas exhibited virtually identical morphology, which could not be precisely classified, but appeared to bridge features of large cell immunoblastic and anaplastic large cell lymphomas. Immunophenotypically the lymphoma cells lacked expression of any B- or T-lymphocyte antigens, but expressed CD45 and the activation antigens CD30, CD38, CD71, and HLA-DR. Clonally rearranged immunoglobulin heavy chain and kappa light chain genes were identified by Southern blot analysis. Molecular studies also revealed Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) genomes and germline configuration of the c-myc protooncogene. In two cases studied cytogenetically, the lymphoma cells manifested complex chromosome abnormalities. These lymphomas are clinically and biologically unique and found predominantly in patients with advanced AIDS, in many cases with pre-existing Kaposi's sarcoma.

Leukemias, myeloma, and other lymphoreticular neoplasms

BACKGROUND

The purpose of this study was to assess the occurrence of various morphologic types of leukemia and myeloma within patient demographic groups and to correlate findings with data-reporting periods and other variables, such as 5-year relative survival.

METHODS

Data from 31,850 cases of multiple subgroups of acute and chronic leukemia, 12,237 cases of myeloma, and 321 cases of "other" lymphoreticular neoplasms were collected by the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program. The data were examined by age, sex, race, age-specific and age-adjusted incidence rate, and patient 5-year relative survival during three reporting periods: 1973-1977, 1978-1982, and 1983-1987.

RESULTS

The age-adjusted incidence rate for all categories of leukemia combined has been constant, but there has been an increase in the relative frequency (percentage) of acute lymphoid leukemia (ALL) in the general population and a rising incidence rate of myeloid leukemia in the black population. The increase of ALL is offset by a decline of acute myeloid leukemias (AMLs) and acute leukemia, not otherwise specified. The age-adjusted rate of ALL in whites, 1.5 per 100,000 per year, is twice that of blacks, 0.8. The rates for each of the major categories of leukemia are considerably higher in males than in females. Five-year survival rates changed very little for leukemias over the 15 years of the study except for ALL, in which there was a marked improvement between the first (1973-1977) (39.1%) and second (1978-1982) (51.3%) reporting period. The SEER data confirm that multiple myeloma is predominantly a disease of late adulthood and occurs more frequently in blacks and males. The incidence rate of multiple myeloma has not changed during the 15 years surveyed. The 5-year relative survival rate has remained nearly constant for multiple myeloma. There is a marked difference in 5-year relative survival rates for patients with plasmacytoma of bone marrow (45.7%), multiple myeloma (25.9%), and plasma cell leukemia (13.0%).

CONCLUSIONS

Shifts in the relative frequencies of leukemia types may have been affected by changes in classification criteria, changes in the use of histologic terms over time, and the expanded use of immunophenotyping and other technology to characterize acute leukemias. Incidence rates and 5-year relative survival rates for myeloma have remained stable.

Secondary acute myeloid leukemia in children with acute lymphoblastic leukemia treated with etoposide

PURPOSE

To describe the occurrence of secondary acute myeloid leukemia (AML) in children with acute lymphoblastic leukemia (ALL) treated with etoposide (VP-16).

PATIENTS AND METHODS

Two hundred five consecutive children with early B-lineage ALL were treated according to the Dallas/Fort Worth (DFW) protocol between January 1986 and July 1, 1991. Therapy included a four-drug induction followed by consolidation and continuation phases of nightly oral mercaptopurine (6-MP) and repetitive courses of divided-dose oral methotrexate (dMTX) and asparaginase (L-asp). Three doses of VP-16 and cytarabine (Ara-C) were given during consolidation and later, during continuation, two doses were given 3 to 4 days apart, every 9 weeks. Intrathecal (IT) chemotherapy was given throughout the treatment period.

RESULTS

Two hundred three of the 205 patients entered remission. Only eight of these 203 children have had a bone marrow relapse (ALL). However, 10 other children have developed secondary AML 23 to 68 months following the diagnosis of ALL. Overall event-free survival (EFS) at 4 years is 79.3% +/- 5.1%, with a risk of secondary AML at 4 years of 5.9% +/- 3.2%.

CONCLUSION

This experience provides strong evidence for a link between epipodophyllotoxin therapy and secondary AML since none of these children received alkylating agent therapy or irradiation. This serious complication raises concern as to the appropriate use of epipodophyllotoxins in the treatment of childhood ALL.

Diagnosis, classification, and course of myelodysplastic syndromes

The myelodysplastic syndromes are bone marrow stem cell disorders that result in disorderly and ineffective hematopoiesis. They are prognostically heterogenous. Approximately one third of cases evolve to acute myeloid leukemia. Many additional cases terminate in severe bone marrow failure. The French-American-British Working Group classification of the myelodysplastic syndromes defines morphologic and prognostic groups. Cytogenetic and in vitro cell culture characteristics are important prognostic indicators.

New technology in laboratory medicine. A call for pathologists to lead the march

Several new technologies are impacting the practice of pathology. Appropriate clinical uses must be defined and standards established. It is vitally important that pathologists play the leadership role in incorporating new diagnostic techniques in the clinical laboratory. To do so may require new knowledge and skills. Pathology associations must support the needs of their members by providing avenues for education and training in new technologies applicable to pathology practice.

Clinical course and prognosis of the lymphoproliferative disease of granular lymphocytes. A multicenter study

Lymphoproliferative disease of granular lymphocytes (LDGL) is a recently recognized, relatively rare atypical lymphocytosis characterized by the presence of over 2000 lymphocytes with cytoplasmic azurophilic granules/mm3 in the peripheral blood. The clinical course is heterogeneous, varying from spontaneous regression to progressive, malignant disease. As a consequence, clinical intervention is not standardized. In a worldwide multicenter study, the authors observed 151 patients with LDGL for a mean follow-up time of 29 months. Forty-three patients were asymptomatic at the time of diagnosis. In the remaining cases, clinical symptoms included fever (41 cases), infections (58), neutropenia (47), anemia (17), and thrombocytopenia (12). In 69 cases, LDGL coexisted with an associated disease. Most patients had a nonprogressive clinical course despite the presence of severe symptoms. In 19 patients, death related to LDGL occurred within 48 months. The authors investigated which features at diagnosis were significantly associated with increased mortality. In the univariate analysis, lymph node and liver enlargement, fever at presentation, skin infiltration, a low (less than or equal to 5000/mm3) or high (greater than 20,000/mm3) peripheral leukocyte count, relatively low (less than or equal to 3000) or high (greater than 7000/mm3) absolute peripheral granular lymphocyte (GL) count, and a low (less than or equal to 15%) percentage of HNK-1-positive cells were found to be predictors of increased mortality. In the multivariate analysis, significant independent predictors were fever at diagnosis, a low (less than or equal to 15%) percentage of HNK-1-positive peripheral blood mononuclear cells (PBMC) and a relatively low (less than or equal to 3000) GL count. These results showed that about 25% of the patients with LDGL were diagnosed after a routine blood count and had no clinical symptoms. The remaining patients were symptomatic, with some experiencing a fatal clinical course. The author's analysis of the significant prognostic features of LDGL may help in understanding the heterogeneous nature of this syndrome.

Bone marrow in malignant lymphoma

The bone marrow examination is useful in the diagnosis and management of patients with malignant lymphoma. Demonstration of marrow lymphoma is dependent on obtaining adequate and properly prepared tissue for examination. The incidence and pattern of marrow disease differ for the various Working Formulation classes of non-Hodgkin's lymphoma (NHL); low grade and high-grade NHL have the highest incidence of marrow involvement at diagnosis. Hodgkin's disease involves the marrow less commonly than NHL and is found in a histologic environment similar to that in lymph node biopsies. Several benign lesions, including reactive lymphoid aggregates, granulomas, immunoblastic lymphadenopathy, and mast cell disease, must be distinguished from NHL or Hodgkin's disease in some instances.

Bone marrow manifestations of peripheral T-cell lymphoma. A study of 30 cases

Morphologic and clinical features of 30 patients with peripheral T-cell lymphoma (PTCL) were studied with particular attention to bone marrow and blood manifestations. Twenty-four (80%) patients had marrow involvement with lymphoma in trephine biopsies at initial diagnosis; two other patients subsequently developed marrow involvement. The bone marrow lesions were diffuse in 58% of the cases and focal, nonparatrabecular in 42%. A morphologic spectrum of lymphoma cells was seen with cases classified into small cell, mixed cell, and large cell/immunoblastic lymphoma. The bone marrow lesions were characterized by a heteromorphous population of lymphocytes, prominent vascularity with endothelial cell proliferation, reticulin fibrosis, and a polycellular infiltrate composed of plasma cells, eosinophils, and histiocytes. The histopathologic features in bone marrow biopsies were not pathognomonic for PTCL; the differential diagnosis may include non-Hodgkin's lymphomas of B-cell type, polymorphous reactive lymphoid lesions, including those from patients with acquired immune deficiency syndrome (AIDS), angioimmunoblastic lymphadenopathy, Hodgkin's disease, and systemic mastocytosis. The patients ranged in age from 13 to 81 years (median, 61 years) and generally presented with constitutional symptoms, lymphadenopathy, and hepatosplenomegaly. Abnormalities in one or more hematologic parameters were common and, in general, related to the degree of bone marrow involvement. Hypocalcemia was found in 40% of the patients studied and hypercalcemia in 4%. The median survival for PTCL patients was 11 months. Patients with small cell lymphoma, large cell/immunoblastic lymphoma, and marked eosinophilia had the shortest median survivals.

Monoclonal antibody study of Philadelphia chromosome-positive blastic leukemias using the alkaline phosphatase anti-alkaline phosphatase (APAAP) technic

The leukemic cells from 15 cases of Philadelphia chromosome-positive blastic leukemia were immunophenotyped by the alkaline phosphatase anti-alkaline phosphatase (APAAP) immunocytochemical technic using nine monoclonal antibodies (MoAb) reactive with various myeloid or lymphoid antigens. On the basis of morphology, cytochemistry, terminal deoxynucleotidyl transferase (TdT) reactivity, and electron microscopy, five of the cases had been classified as lymphoid; eight, myeloid; one, mixed myeloid-lymphoid; and one, undifferentiated. The blasts from all five lymphoid cases were reactive with lymphocyte differentiation antigen MoAb, and four of five reacted with MoAb to anti-common acute lymphoblastic leukemia-associated antigen (CALLA) (BA3). The blasts from all eight myeloid cases were reactive with MY7, a marker of myelomonocytic differentiation. Some of the blasts from three of the eight myeloid cases reacted with HP1-1D and AP3, markers of megakaryocytic differentiation; megakaryocyte differentiation was confirmed by electron microscopy. In the case classified as mixed myeloid-lymphoid, the blasts showed morphologic and immunophenotypic heterogeneity; ultrastructural studies demonstrated lymphoid, basophil, and erythroid differentiation. The blasts from the case classified as undifferentiated were immunophenotypically heterogeneous. In all cases in which the leukemic cells were also immunophenotyped by flow cytometry, the results correlated well with those obtained by the APAAP technic. The APAAP technic is a reliable method for immunophenotyping leukemias. Advantages of this method include its applicability to routinely prepared blood and bone marrow smears and cytocentrifuge preparations, lack of endogenous peroxidase background staining, and a permanent record.

Granulated T cell lymphocytosis with neutropenia: malignant or benign chronic lymphoproliferative disorder?

The clinical, morphological, immunologic, and cytogenetic features of seven cases of chronic granulated T cell lymphocytosis with neutropenia were studied. The disorder was characterized by moderate blood and bone marrow lymphocytosis, neutropenia, polyclonal hypergammaglobulinemia, splenomegaly, absence of lymphadenopathy, and a chronic, relatively stable clinical course. The proliferative lymphocytes manifested a cytotoxic/suppressor T lymphocyte phenotype. In two of four cases studied, blood lymphocytes showed clonal chromosome abnormalities. One patient treated with pulse steroid therapy had reversal of lymphocytosis and severe neutropenia with subsequent resolution of an intractable infection. The lymphocytosis and neutropenia recurred when steroids were withdrawn. Six of the seven patients were living three months to 17 years from diagnosis; one died at 4.3 years of an unrelated cause. Five of the patients, including the two with lymphocyte chromosome abnormalities, had persistent lymphocytosis and neutropenia from three months to 13 years from diagnosis. In two patients, the disease appears to have undergone spontaneous regression. No differences in clinical presentation or the morphological or immunologic characteristics of the proliferative lymphocytes were apparent between those patients with lymphocyte chromosome abnormalities and persistent disease and those who had a spontaneous regression. The finding of clonal chromosome abnormalities in the blood lymphocytes of two of the patients in this study suggests a neoplastic origin for chronic granulated T cell lymphocytosis with neutropenia. However, apparent spontaneous regression in two patients, one after 11 years, lends support to a chronic reactive or immunoregulatory disorder as the etiology. It is probable that cases of granulated T cell lymphocytosis with neutropenia, although morphologically and immunologically similar, are biologically heterogeneous.

The accelerated phase of Chediak-Higashi syndrome. An expression of the virus-associated hemophagocytic syndrome?

The clinical and pathologic findings of four patients with Chediak-Higashi syndrome in the accelerated phase were studied in order to clarify the nature of this enigmatic process. Fever, lymphadenopathy, hepatosplenomegaly, and cytopenias were present in every patient. All cases demonstrated extensive parenchymal infiltrates in many organs composed of benign-appearing histiocytes manifesting hemophagocytosis accompanied by lymphocytes and plasma cells. Studies in one patient suggested a viral etiology with the findings of a low blood lymphocyte OKT4 to OKT8 ratio, acquired loss of lymphocyte response to mitogens, the presence of Epstein-Barr virus genome in the mononuclear cells of lymph node, blood, and bone marrow, and possible clinical responses to acyclovir. It is concluded that the accelerated phase of Chediak-Higashi syndrome may be the clinicopathologic expression of the virus-associated hemophagocytic syndrome.

Therapy-related acute myeloid leukemia and myelodysplastic syndrome: a clinical and morphologic study of 65 cases

This study consists of 65 patients (pts) who developed a myelodysplastic syndrome (MDS) (39 pts) or acute myeloid leukemia (AML) (26 pts) following chemotherapy and/or radiotherapy; the interval from the onset of therapy to bone marrow abnormality ranged from 11 to 192 months (median, 58). Thirty-three patients had been previously treated for lymphoproliferative diseases, 29 for carcinoma, and three for a nonneoplastic disorder. Approximately 30% of the cases presenting in the MDS phase evolved to AML in one to 12 months (median, 3.5). The AML in 49% of the cases was not readily classified according to French-American-British (FAB) criteria; the primary difficulty in classification related to the involvement of multiple cell lines. Among the cases that could be classified, all FAB types were represented except for M1; M2 was the most frequent type. Clonal chromosome abnormalities were found in marrow specimens from 22 of 24 (92%) patients studied with G banding; 11 had abnormalities of chromosomes 5 and/or 7. The median survival for all patients was four months with no significant difference between those treated and not treated with antileukemic therapy. The median survival was three months for the patients presenting with AML, six months for the patients with AML following an MDS, and four months for the patients with an MDS that did not evolve to AML. The findings in the present study suggest that there are three stages of therapy-related panmyelosis: (1) pancytopenia with associated myelodysplastic changes, (2) a frank MDS, and (3) overt AML. Many patients will present in the stage of overt AML that differs from de novo AML primarily by the high incidence of trilineage involvement, difficulty in classification, frequent cytogenetic abnormalities, and poor response to antileukemic therapy. The myelodysplastic phase, with or without evolution to acute leukemia, is a highly lethal disease with a median survival comparable to that of the patients who present with AML.

Transformation of chronic myelogenous leukemia: clinical, morphologic, and cytogenetic features

The morphologic, cytogenetic, and clinical features of 58 patients with transformation of Philadelphia chromosome (Ph1) positive chronic myelogenous leukemia (CML) were evaluated. The patients were divided into two groups on the basis of blood and marrow findings: blast crisis and subacute transformation. The evolution of the leukemic process in 41 patients was classified as blast crisis based on one of three criteria: 30% or more blasts in blood and/or marrow smears, intramedullary focus of blast transformation in a marrow trephine biopsy, or blast transformation in an extramedullary site. The 17 patients with subacute transformation of CML had a deteriorating clinical and hematologic picture but did not manifest any of the criteria for blast crisis. The blood and marrow findings in this group of patients were characterized by several qualitative and quantitative changes, including anemia, thrombocytopenia, decreasing leukocyte count, increasing basophilia, myelofibrosis, dysplastic alterations in hematopoietic cells, and increased blasts which, however, never exceeded 25%. Chromosome abnormalities in addition to the Ph1 were found in 65% of the patients with blast crisis and 86% of the patients with subacute transformation. The 41 patients with blast crisis had a median survival of nine weeks; the 17 with subacute transformation had a median survival of 26 weeks. The shortest median survival for patients with blast crisis, four weeks, occurred in the patients with myeloid blast crisis with chromosome abnormalities in addition to the Ph. The longest median survival, 52 plus weeks, occurred in patients with lymphoid blast crisis with only the Ph1 at transformation.

Systemic mastocytosis. Extracutaneous manifestations

The clinical, radiologic, ultrastructural, and histopathologic findings in 14 patients with systemic mastocytosis were evaluated. Seven patients had evidence of urticaria pigmentosa (UP) and seven patients presented with no recognizable cutaneous lesions. There were no major clinical differences between patients with or without UP except for splenomegaly, which was present in one/seven patients with UP and five/seven patients without UP and the median age, 44 in patients with UP, and 75 in patients without UP. Bone marrow involvement was present in 13/13 specimens studied. Involvement was both focal and diffuse. The focal involvement occurred frequently in a perivascular and paratrabecular location. The diffuse involvement resembled myelofibrosis. Involved lymph nodes exhibited prominent sinusoidal and paracortical infiltration by mast cells. Splenic involvement was characterized by fibrosis occurring both focally and diffusely. The focal splenic involvement was perivascular and involved both the red and white pulp in a nonpreferential manner. Liver specimens showed prominent portal fibrosis. The morphology of the mast cells in the different lesions varied considerably; some were typical, others were spindle-shaped, and some resembled histocytes. The mast cells reacted positively with toluidine blue and chloroacetate esterase. Six patients had radiologic changes: three were osteoblastic, two osteolytic, and one osteoblastic and osteolytic. Two patients developed a poorly differentiated lymphoreticular tumor and one a myeloproliferative disorder after the diagnosis of mastocytosis.

Terminal deoxynucleotidyl transferase (TdT)-positive cells in bone marrow in the absence of hematologic malignancy

An indirect immunofluorescent technic was used to identify cells with terminal deoxynucleotidyl transferase (TdT) activity in bone marrow smears from 169 patients without a clinically or morphologically apparent hematologic malignancy: 73 normal individuals, 27 bone marrow transplant recipients, 25 with neuroblastoma or retinoblastoma, 19 with acute lymphoblastic leukemia (ALL) in remission, and 25 with miscellaneous benign conditions. In selected cases, additional bone marrow smears were investigated for TdT-positive cells, using one of two immunoperoxidase methods, the peroxidase-antiperoxidase (PAP) technic or the avidin-biotin-peroxidase complex (ABC) technic. Superior preparations were obtained using the ABC technic. Fifty-eight of the 169 smears contained 2% or more TdT-positive cells, range 2%-20%. The morphologic characteristics of the TdT-positive cells in phase-contrast illumination and in Wright's-Giemsa counterstained immunoperoxidase preparations indicated that many of these cells may be hematogones. TdT-positive cells in the bone marrow of a patient with ALL in remission following chemotherapy or bone marrow transplantation do not necessarily denote relapse.

Acute leukemia associated with the t(4;11) chromosome rearrangement: ultrastructural and immunologic characteristics

The acute leukemia associated with the t(4;11) chromosome rearrangement is characterized by relatively consistent clinical features: occurrence primarily in young individuals, hyperleukocytosis, and poor response to therapy. This study describes the morphological, ultrastructural, and immunologic characteristics of the leukemic cells from ten patients with this type of leukemia. The morphological features of the leukemic blasts vary from lymphoid-appearing to monocytic. Ultrastructurally and cytochemically, some of the lymphoid-appearing blasts possess features of myeloid origin. The immunologic phenotype is characteristically E- SIg- CALLA- BA-1- BA-2+ HLA-DR+ and TdT+. These findings suggest that the t(4;11)-associated acute leukemia represents a proliferation of an early myeloid progenitor cell.

Philadelphia chromosome-positive blastic leukaemia: ultrastructural and ultracytochemical evidence of basophil and mast cell differentiation

Ultrastructural, ultracytochemical, immunologic and biochemical studies were performed on leukaemic cells from 41 patients with Philadelphia chromosome-positive blastic leukaemia; 28 patients were in blast transformation of chronic myelogenous leukaemia and 13 patients presented with 'acute' leukaemia. The patients were divided into two morphologic groups, lymphoid (16 cases) and myeloid (25 cases), on the basis of light microscopy and cytochemistry. All lymphoid cases studied for the presence of CALLA (10 patients) and TdT (11 patients) were positive. Two of 13 myeloid cases studied were TdT positive. The blasts from 10 of 16 lymphoid cases contained immature basophil/mast cell granules on ultrastructural examination. Peroxidase-positive 'lymphoid' blasts were noted in three of seven patients studied by ultracytochemical techniques. The reactivity was primarily confined to granular structures. Of the 25 cases in the myeloid group, blasts from 14 cases showed basophil/mast cell differentiation, nine cases showed neutrophil/monocyte features, and two cases were megakaryoblastic. Distinct patterns of ultrastructural peroxidase positivity were seen in the seven myeloid cases studied. In basophil/mast cell precursors the reactivity was primarily confined to granules; neutrophil precursors showed reactivity in the nuclear envelope, rough endoplasmic reticulum (RER), golgi and granules; in megakaryoblasts, only the nuclear envelope and RER were positive while the granules were consistently negative.

15;17 Translocation in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a relatively rare subtype of leukemia that has been reported to be associated with a specific chromosome abnormality, t(15;17). It has been suggested that this translocation may have a geographical distribution and its presence may signify a poorer prognosis. In this present series of 14 patients with APL, 9 patients (64%) had the t(15;17) and 5 did not; however, no significant differences in clinical features or outcome could be found between those who did and those who did not express the translocation. When ethnic backgrounds were explored, no differences were found. More cases of the t(15;17) were found in recent years (7 of 8 patients studied since 1978 compared to 2 of 6 before 1978). This corresponded to changes made in our cytogenetic techniques suggesting that the finding of the t(15;17) may be a function of technique, rather than a real difference in disease entities, and all patients with APL may have the t(15;17) when appropriately studied.

Bone marrow and blood involvement by lymphoma in relationship to the Lukes--Collins classification

The incidence, pattern, extent, and morphology of bone marrow involvement in 176 cases of non-Hodgkin's lymphoma (NHL) were studied in relationship to the Lukes--Collins classification. Ninety percent of the cases were B-cell lymphomas; 10% were T-cell lymphomas. In 53% of cases there was bone marrow involvement by lymphoma at diagnosis. Marrow involvement was most frequently found in the small lymphocyte (B), small cleaved follicular center cell (FCC), and convoluted lymphocyte lymphomas. Frequently, the extent of bone marrow biopsy replacement by lymphoma was less than 30%; the pattern of infiltration was predominantly focal (70%). Cytologic agreement between lymph node and bone marrow specimens was always present in small lymphocyte (B), small noncleaved FCC, convoluted lymphocyte, and lymphoepithelioid cell lymphomas. Cytologic diversity between lymph node and marrow was noted in 20% of small cleaved FCC, 40% (2/5) of large cleaved FCC, and 38% (3/8) of large noncleaved FCC lymphomas. In 79% of all involved cases, both bone marrow biopsy sections and aspirate smears were diagnostic of NHL; only biopsy sections were positive in 18%, and only smears were positive in 3%. The Lukes--Collins classification predicts a high incidence of bone marrow involvement for small lymphocyte (B), small cleaved FCC, and convoluted lymphocyte lymphomas.

Acute promyelocytic leukaemia: a study of 39 cases with identification of a hyperbasophilic microgranular variant

Thirty-nine cases of acute promyelocytic leukaemia (APL) were divided into two morphological subgroups, typical hypergranular APL (31 cases) and microgranular APL (eight cases, 21%). The leukaemic cells in the microgranular APL cases were characterized by striking nuclear folding or lobulation; granulation was present in most of these cells but was less abundant and finer than in typical APL. In three microgranular APL cases a distinctive small leukaemic promyelocyte with unusual nuclear lobulation and deeply basophilic cytoplasm containing few or no visable granules was the predominant leukaemic cell. This small hyperbasophilic promyelocyte was also present as a minor population of cells in the other five microgranular APL case and in 28 of the 31 typical APL cases. Ultrastructurally the most abundant promyelocytes in microgranular APL had smaller and usually fewer granules than in typical APL; other characteristic ultrastructural features of APL were found with equal frequency. The median blood leucocyte count was significantly higher in microgranular APL, 83.0 x 10(9) x 10(9)/l, than in typical APL, 1.8 x 10(9)/l (P less than 0.01). The median duration of complete remission (CR) for microgranular APL, 6.5 months, was shorter than the 21 + month median CR for typical APL. The morphological characteristics of microgranular APL may mimic those of myelomonocytic leukaemia; however, the presence of cells with multiple Auer rods, large inclusions of Auer-like material and the small hyperbasophilic promyelocytes are important distinguishing features. In equivocal cases cytochemistry, electron microscopy and cytogenetic studies may verify the diagnosis.

Glucocorticoid receptors and in vitro responses to glucocorticoid in acute nonlymphocytic leukemia

Early clinical studies in which glucocorticoids were used alone in the treatment of acute nonlymphocytic leukemia (ANLL) reported a wide range of responses from remission in some patients to dramatic aggravation of the disease in others. In the hopes of identifying those patients likely to derive therapeutic benefit from glucocorticoids, we have studied glucocorticoid receptors and in vitro responses to glucocorticoids in 36 previously untreated adults with ANLL. The leukemic blasts of all patients contained glucocorticoid receptors (range, 4,300 to 28,400 total receptor sites per cell; median, 8,800). These receptors were similar in all respects studied to those from a variety of other normal and malignant tissues. There was little difference between receptor levels among the various French-American-British categories. In vitro responses to glucocorticoid were observed in leukemic blasts of 26 of 28 cases studied. These responses varied from near complete cell killing to stimulation of proliferation. Since the cells of patients with ANLL have about the same number of receptors as do cells from patients with acute lymphoblastic leukemia and these receptors are capable of mediating physiological responses in vitro, it is unlikely that qualitative or quantitative receptor defects underlie the relative resistance to glucocorticoid therapy of ALL compared to acute lymphoblastic leukemia. However, the broad range of in vitro responses and receptor levels suggests that these studies might be useful in identifying those patients with ANLL likely to derive benefit from steroid therapy.

Chromosomal abnormalities in acute lymphoblastic leukemia

Chromosome abnormalities in acute lymphoblastic leukemia (ALL) and their possible clinical significance are briefly reviewed based upon the literature and 60 cases studied at the University of Minnesota. Almost all cases of ALL appear to demonstrate clonal abnormalities; the major abnormal clone is usually hyperdiploid or pseudodiploid. Among cases of non-T, non-B ALL, at least four translocations appear to be present with an increased frequency: t(9;22); t(4;11); t(11;14); and t(1;3). Patients with these translocations appear to have unique clinical and laboratory findings. Although the presence of abnormal clones does not seem to influence remission duration, the nature of the abnormality does. Patients whose leukemias demonstrate predominantly a pseudodiploid abnormal clone or a translocation have significantly shorter first remissions. Most importantly, among patients with non-T, non-B ALL, the presence or absence of translocations may separate poor responders from good responders.

Use of monoclonal antibodies, morphology, and cytochemistry to probe the cellular heterogeneity of acute leukemia and lymphoma

A combined immunological, morphological, and cytochemical approach to the study of malignant cells in patients with acute leukemia and lymphoma is presented. Newly produced monoclonal antibodies that bind to antigens of human mononuclear cells (TA-1), or B-lymphocytes (BA-1) were used to study malignant cells from patients with acute lymphoblastic leukemia (ALL). acute myelocytic leukemia, acute myelomonocytic leukemia, and chronic lymphocytic leukemia. Results in lymphoid leukemia-lymphoma patients were compared with other immunological markers and indicate that the major groups of ALL and childhood non-Hodgkin's lymphoma are T-ALL, pre-T-ALL, pre-B-ALL, B-ALL, and non-T, non-B-ALL. In addition, each major group had multiple phenotypes when analyzed with seven immunological markers including the erythrocyte rosette receptor, surface immunoglobulin, cytoplasmic immunoglobulin M, the early lymphocyte-acute lymphoblastic leukemia antigen, monoclonal antibody TA-1, monoclonal antibody BA-1, and a monoclonal antibody against HLA-DR. While immunological heterogeneity was demonstrable within each group, distinct biological behavior was observed, with T-ALL and B-ALL generally presenting as "lymphomas" and the others presenting as "leukemias." Morphological analysis using the French-American-British classification provided independent information in the definition of groups with differing clinical behavior. Cytochemical analyses demonstrated focal paranuclear staining of leukemia cells with acid phosphatase in 73% of T-ALLs and 6% of non-T, non-B-ALLs.

Polymorphic diffuse B-cell hyperplasias and lymphomas in renal transplant recipients

The lymphoproliferative processes that developed in five renal transplant recipients were studied in an attempt to characterize and classify them morphologically. Nine surgical specimens, hematological material on all patients, and autopsy specimens from three patients were available. Studies performed included: conventional histopathology; evaluation of cell markers (immunoglobulins and sheep erythrocyte, complement, and Fc receptors) and cytoplasmic immunoglobulins (peroxidase-antiperoxidase technique); ultrastructural examination; and karyotype analysis. The lymphoid lesions in our patients shared marked cytological polymorphism (small and large cells, of both follicular center and "medullary" type) and polyclonal B-cell features, which indicated a common reactive nonneoplastic origin. However, other features, such as morphological atypia of the immunoblasts, extensive necrosis, chromosomal aberrations, and an incipient monoclonal component suggested the development of lymphoma in some of these lesions. In contradistinction, the abundance of typical immunoblasts was a feature that seemed to correlate with the clinical activity of the disease rather than with the biological malignancy. The multiplicity of B-cell types and the presence of a follicular center cell component with diffuse distribution, as well as the extensive necrosis in the malignant forms, seem to differentiate morphologically the lymphoproliferative processes arising in transplant recipients from both the hyperplasias and the lymphomas developing in immunologically normal hosts. For the former, we propose the terms of "polymorphic diffuse B-cell hyperplasias" and "polymorphic B-cell lymphomas."

Ultrastructural characteristics of therapy-related acute nonlymphocytic leukemia: evidence for a panmyelosis

Leukemic cells from 13 patients with therapy-related acute nonlymphocytic leukemia (ANLL) were studied by electron microscopy. All of the patients had radiotherapy, and/or alkylating agent chemotherapy for other neoplastic disease 25 to 182 months prior to the diagnosis of ANLL. All cases manifested ultrastructural evidence of a panmyelopathy. All marrow cell lines exhibited nuclear--cytoplasmic asynchrony and abnormalities of cell size. Developing granulocytes exhibited decreased primary and/or secondary granule formation and abnormal granules characterized by irregular shape, large size and internal membranous lamellae. Monocytes showed perinuclear bundles of microfilaments. In some cases, the predominant leukemic blasts showed evidence of early basophil granule development which was not appreciated in light microscopy. Abnormalities in erythroid cells included abundant intracristal mitochondrial iron, large vacuoles, infoldings of redundant membrane and membrane-bound nuclear blebs and intranuclear clefts. Megakaryocytes manifested decreased numbers of granules and demarcation membranes. Excessively large platelets with decreased or abnormal granules were identified; giant compound granules with irregular contour and variable electron density were present. Several of the changes in the developing hematopoietic cells were similar to those described in preleukemia and in certain nonneoplastic disorders. The consistent panmyelosis in therapy-related ANLL together with several uniform clinical features defines a specific clinicopathologic entity.

VP 16-213 and cyclophosphamide in the treatment of refractory acute nonlymphocytic leukemia with monocytic features

The treatment of refractory acute nonlymphocytic leukemia remains a major clinical problem in leukemia therapy. VP 16-213 is an investigational agent that may have specificity for monocytic blasts, and the combination of VP 16-213 and cyclophosphamide is synergistic in experimental leukemia. Seven patients with highly refractory acute nonlymphocytic leukemia, which demonstrated monocytic features, were treated with a combination of VP 16-213 and cyclophosphamide after they had failed to respond to multiple courses of intensive induction regimens. Three complete remissions and one partial remission were achieved. The times to complete remission were 21, 23, and 34 days. The durations of complete remission were 5, 9, and 12+ months. Myelosuppression was the most common side effect; one patient experienced nausea and stomatitis. There were no documented infections or hemorrhage, and no one died as a result of therapy. This combination is both well tolerated and effective in the treatment of refractory leukemia with monocytic features.

Malignant histiocytosis: A light- and electron-microscopic and histochemical study

The light- and electron-microscopic features and histochemical characterization of three consecutive cases of malignant histiocytosis (MH) are reported. Each case demonstrated involvement of lymph nodes and bone marrow. In the lymph node, the characteristic destructive sinusoidal pattern of involvement by cytologically malignant cells was present. Phagocytosis by malignant cells was rare and most readily appreciated in the imprint preparations. The major problem in differential diagnosis related to defining the histiocytic nature of the malignant cells. This question was resolved by the demonstration of diffuse cytoplasmic staining with the nonspecific esterase and acid phosphatase reactions as well as the ultrastructural demonstration of histiocytes. Although benign, reactive histiocytes were positive, malignant histiocytes did not stain for lysozyme by an immunoperoxidase technique. In contrast to the uniform appearance of these cases, many reports of MH in the past have consisted of heterogeneous cases with variable histologic appearances from a proliferation of predominantly mature histiocytes with marked phagocytosis to cytologically malignant cells with little apparent functional activity. This variation in histologic appearance is due in part to inclusion of cases of reactive histiocytic proliferations, including the recently described virus-associated hemophagocytic syndrome.

Ultrastructural features of basophil and mast cell granulopoiesis in blastic phase Philadelphia chromosome-positive leukemia

Ultrastructural and ultracytochemical studies were performed on blood and bone marrow specimens from 18 patients with Philadelphia chromosome-positive blastic leukemia; 7 patients were in blast transformation following a typical history of chronic myelogenous leukemia and 11 patients presented with "acute leukemia." The patients were divided into 2 morphologic groups on the basis of light microscopic and cytochemical observations. In group I, which consisted of 11 patients, the proliferating cells were "lymphoid" in appearance and demonstrated many cytochemical, biochemical, and immunologic features similar to those of the lymphoblasts of non-T, non-B acute lymphoblastic leukemia. In group II, which consisted of 7 patients, the proliferating cells were myeloid in appearance. On the basis of ultrastructural observations, the 11 group I patients were divided into 2 subgroups, A and B. Subgroup IA, consisting of 5 patients, was characterized by blasts that demonstrated no differentiating features. In subgroup IB, consisting of 6 patients, 20-30% of the leukemic cells contained inclusions that resembled leukemic mast cell or basophil granules. The leukemic cells in the 7 group II patients manifested myeloid characteristics by light microscopy and prominent basophil and mast cell granulopoiesis by electron microscopy. Abnormalities of other myeloid cell lines were also observed in both the lymphoid and myeloid groups of patients.

Philadelphia chromosome positive childhood acute lymphoblastic leukemia

In a 3-yr period, the Philadelphia chromosome (Ph1) was found in 4 of 43 children with acute lymphoblastic leukemia (ALL) in whom chromosomes were studied at diagnosis. The clinical, morphological, cytochemical, and immunologic findings in the Ph1-positive (PH1+) CASES WERE CONsistent with typical childhood ALL, indicating that identification of cases requires chromosome studies. A review of all reported cases of Ph1 + childhood ALL shows that Ph1 + patients are older and have higher initial platelet and white blood cell counts (WBC) than most children with ALL. However, a life table comparison between the reported cases of Ph1 + ALL in children and randomly selected age-, sex-, and WBC-matched controls with ALL shows the duration of first marrow remission to be significantly shorter (p less than 0.02) for the Ph1 + cases Ph1 + ALL is a distinct subtype of childhood ALL that is not rare and can be identified only by cytogenetic studies. The prognosis is poor. Cytogenetic studies should be done prospectively in a large group of children with ALL to define further the subgroup of patients and to confirm the findings of this retrospective analysis.