Hand mirror variant of adult acute lymphoblastic leukemia. Evidence for a mixed leukemia.

Blast cells from a female patient with acute lymphoblastic leukemia-hand mirror variant were examined using various techniques, including light and ultrastructural morphologic examination, cytochemical analysis, surface antigen characterization, cytogenetic analysis, and gene rearrangement studies. The blast cells were found to be pre-B cells (CD19+ and Tdt+) that also expressed the myeloid antigens CD13 and CD33 and demonstrated a heavy chain immunoglobulin gene rearrangement. Cytogenetic studies revealed a t(11;19) translocation previously described in biphenotypic leukemias. A subset of acute lymphoblastic leukemia-hand mirror cells has been previously defined and includes predominately female patients with an indolent course. The authors' findings place this case, a mixed leukemia, within that subgroup. The possibility of mixed lineage should be considered in future cases of hand mirror variants of adult acute lymphoblastic leukemia. Furthermore, hand mirror morphologic features in any case of acute leukemia should alert the hematopathologist/hematologist to the possibility of mixed lineage.

Acute erythroleukemia: evaluation of 48 cases with reference to classification, cell proliferation, cytogenetics, and prognosis.

We evaluated 48 archival cases of acute erythroleukemia and divided them into 3 groups: M6a, corresponding to the traditional French-American-British M6 category; M6b, which is pure erythroleukemia; and M6c, in which myeloblasts and pronormoblasts each account for more than 30% of cells by the French-American-British exclusion criteria. No significant differences were noted among the subtypes for ratio of males to females; age; or exposure to toxins, alcohol, or both. However, compared with the patients in the M6a group, patients in the M6b and M6c groups demonstrated a statistically significant increase in cytogenetic aberrations, proliferation markers (proliferating cell nuclear antigen and Ki67), and ringed (type III) sideroblasts. Marked survival differences were noted between the M6a (30.1 +/- 29.5 months) and M6b (3.15 +/- 4.2 months) groups, with patients in the M6c group demonstrating an intermediate prognosis (10.5 +/- 12.7 months). Chemotherapeutic regimens induced remission in all treated patients in the M6a and M6c groups but did not appear to affect the M6b group. However, the patients in the M6c group remained in remission for a significantly shorter period of time than did patients in the M6a group. Overall, survival appeared to depend on the ratio of pronormoblasts to myeloblasts at diagnosis and demonstrated a rapid decline with increasing pronormoblast and decreasing myeloblast counts. We must, therefore, devise chemotherapeutic regimens that target both blastic components of this disease.

Acute leukemia and related entities. Impact of new technology.

Twenty-seven cases of acute leukemia and related entities were evaluated by morphologic examination, cytochemical study, terminal deoxynucleotidyltransferase study, immunophenotyping, cytogenetic analysis, ultrastructural cytochemical study, and gene rearrangement analysis to determine the impact on the determination of the French-American-British (FAB) classification and the definitive diagnosis. The definitive diagnosis contained prognostic, diagnostic, and treatment information beyond the FAB classification that affected the disease course and patient management. All diagnostic variables were evaluated in each case and were labeled essential, ambivalent, supportive, or noncontributory. Except for gene rearrangement analysis, all variables we studied contributed essential data to establish the definitive diagnosis. Ambivalent findings were rare but could be explained with the knowledge of the total data. All variables, except cytochemical study, whose results were almost always essential, contributed supportive data. Noncontributory data only occurred with cytogenetic analysis in cases that demonstrated normal karyotypes. The FAB classification was established in 20 (74%) of the cases by use of morphologic examination, cytochemical study, and terminal deoxynucleotidyltransferase study. With use of the same variables, however, the definitive diagnosis, whose determination required all data, was established in only 15 (55.5%) of the cases. The addition of immunophenotyping increased the definitive diagnosis to 25 (92.5%) of the cases. The use of ultrastructural myeloperoxidase and platelet peroxidase analysis enabled us to definitively diagnose the remaining two cases (27 cases [100%]). Cytogenetic analysis revealed four cases in which essential information was added to the diagnosis. However, because the cytogenetic information usually was not immediately available, the result did not affect the immediate diagnosis or treatment. Surprisingly, the gene rearrangement studies did not yield essential data in any case and in a few cases contributed ambivalent data. This finding should not exclude gene rearrangement analysis in selected cases; however, the data should always be interpreted in light of all clinical and laboratory findings. This study clearly demonstrates the importance of a multifaceted approach to the understanding of the acute leukemias and related entities and shows the impact of newer technologies on reaching a definitive diagnosis.

Scleredema and smoldering myeloma.

A 46-year-old white man had classic findings of scleredema; subsequently, a monoclonal immunoglobulin G lambda light chain was detected in his serum. Findings of a bone marrow biopsy specimen revealed that he had an increased percentage of plasma cells, some of which were atypical. A diagnosis of scleredema and smoldering myeloma was made.

Effects of multidrug resistance gene expression in acute erythroleukemia.

Acute erythroleukemia is a relatively rare disorder of a multilineal nature. Patients with this type of leukemia traditionally have been treated with a standard myeloid protocol, with a wide variation in prognosis between M6a, which has a similar prognosis to acute myelogenous leukemias, and M6b, with an extremely poor outcome despite aggressive therapy. Forty-eight archival cases of acute erythroleukemia, subtypes M6a (the traditional FAB-M6), M6b (pure erythroleukemia), and M6c (>30% myeloblasts and >30% pronormoblasts by FAB exclusion criteria), were evaluated for multidrug resistance gene (MDR-1) status. Findings were correlated with clinical course and karyotypes. Immunohistochemical stain for the protein product of MDR-1, P-glycoprotein, was variably positive in 11 of 23 patients with M6a, as well as in all of the patients with M6b (strongly positive) and M6c (weakly positive). P-glycoprotein expression positively correlated with unfavorable cytogenetic aberrations, poor response to chemotherapeutic agents, and short survival. Most significant was that P-glycoprotein expression demonstrated a negative additive effect on response to treatment and prognosis with unfavorable cytogenetic anomalies. P-glycoprotein expression and multiple cytogenetic anomalies most probably contribute to the resistance to chemotherapy and poor survival characteristic of the patients with M6b (mean survival, 3.15 +/- 4.2 mo) and M6c (mean survival, 10.5 +/- 12.7 mo). Because patients with M6b and M6c have increased numbers of pronormoblasts in their bone marrow and past chemotherapeutic attempts have failed, chemotherapy directed at these cells is appropriate. Additional therapy directed toward the MDR-1 gene and its protein product seems indicated from our findings.

Diagnosis and characterization of acute erythroleukemia subsets by determining the percentages of myeloblasts and proerythroblasts in 69 cases.

Acute erythroleukemia (FAB M6) is a rare heterogeneous disease with an increase in red cell precursors and myeloblasts. Three subsets have been described: M6A (myeloblast-rich erythroleukemia); M6B (proerythroblast-rich erythroleukemia); and M6C (myeloblast- and proerythroblast-rich mixed variant). This study was undertaken to define and compare the clinical courses and survival outcomes among M6A, M6B, and M6C variants of erythroleukemia. Sixty-nine cases of M6 leukemia were categorized as consisting of >/=50% erythroid of all nucleated cells and M6A with >/=30% myeloblasts/nonerythroid component; M6B with >/=30% proerythroblasts/erythroid component; and M6C with >/=30% myeloblasts and >/=30% proerythroblasts. The demographics, cell type distribution, and survival (mean +/- sd) of these groups were compared. There were 32 M6A, 26 M6B, and 11 M6C patients. No significant difference was seen among the groups in age, sex, or treatment. Compared to M6A, both the M6B (P< 0.0001) and M6C (P< 0.0001) variants showed a statistically significant increase in the percentage of bone marrow erythroid cells, proerythroblasts, and the proerythroblasts/erythroid ratios. Comparing the groups for survival, M6B (3 +/- 3.6 months) versus M6A (25 +/- 28 months), P< 0. 002, and M6C (10 +/- 13 months) versus M6A, P< 0.01 had a poorer prognosis. Calculating the proerythroblasts as a component of total bone marrow erythroids provides a complimentary method for delineating the pure red cell erythroleukemia (M6B) and mixed variant (M6C), similar to that for the myeloid/erythroid (M6A) leukemia. Now that it is possible to delineate erythroleukemia subtypes, innovative treatments are indicated to target the malignant erythroid population, which is resistant to myeloid-based therapies.