Vlasta Hitrec

Acute promyelocytic leukemia M3: cytomorphologic, immunophenotypic, cytogenetic, and molecular variants.

Acute promyelocytic leukemia (APL) M3 is an acute myeloid leukemia (AML) subtype characterized by proliferation of malignant promyelocytes with mature myeloid immunophenotype and the translocation t(15;17)(q22;q11), which results in the fusion of retinoic acid receptor-alpha (RARalpha) gene on chromosome 17 and the gene PML on chromosome 15. There are three M3 morphologic variants: the typical hypergranular form and the microgranular and basophilic variants. Although most leukemic cells in M3 patients express t(15;17), other cytogenetic abnormalities have also been reported. Also, there are three molecular variants of the PML/RARalpha transcript (bcr1, bcr2, bcr3). Blasts had typical hypergranular appearance (13 patients) with a mature myeloid immunophenotype (HLA-DR(-),CD13(+), and/or CD33(+)) (10 patients) in the majority of patients with M3 followed in this study. The typical translocation [t(15;17)(q22;q11)] was detected by cytogenetic analysis in 5 M3 patients, but PML/RARalpha was positive in 13 out of 15 patients, as assessed by RT-PCR (8 patients with bcr1 and 5 with bcr3 subtype). Cytogenetic diversity was found in three patients (1 with t(17;17), 1 with +8, and 1 with add (7)(q22); -7; +8). According to many studies, leukemic cell heterogeneity in APL influences the clinical outcome of disease. The analysis of certain leukemic cell characteristics on the clinical outcome in our study revealed that patients with bcr3 had shorter medians of first remission and survival in comparison to patients with the bcr1 isoform of PML/RARalpha. Also, the clinical relapse of disease in 4 APL patients with reverted PML/RAR alpha positivity is consistent with the view that detection of PML/RARalpha by RT-RCR in patients in remission implies a poor prognosis. On the contrary, lack of detection of PML/RARalpha by RT-PCR at least three times is a sign of long remission and survival.

Four siblings with Robert's syndrome

A Yugoslav family with one female and three male children with Roberts syndrome (RS) is described. To our knowledge, there is no other family with four siblings presenting this genopathy. Most of the symptoms of the fourth sibling were identical to those found in the SC syndrome, suggesting the same genetic origin. The same chromosomal changes which were discovered in the third sibling were also found in the fourth sibling. These chromosomal abnormalities could prove useful for antenatal diagnosis.

Risk estimates for balanced reciprocal translocation carriers--prenatal diagnosis experience

An analysis was performed on 40 families at risk for an unbalanced rearrangement in the fetus because one of the parents is a reciprocal translocation carrier. The overall risk at second trimester prenatal diagnosis was 14% (8/57). The individual risks for unbalanced offspring at second trimester prenatal diagnoses and at birth were estimated using empirical data by Stengel‐Rutkowski et al. (1988). The risks at birth ranged from 0%–21.6%. Most reciprocal translocations (22 or 55%) were at low risk. Without risk (7 or 17.5%), medium risk (6 or 15%) and high risk (5 or 12.5%) translocations were about equally represented and relatively infrequent. The analysis shows that the mode of ascertainment as well as the measurement of lengths of observed or probable imbalances cannot serve as a reliable risk predictor in individual counselling. In the translocations ascertained through spontaneous abortions the risk is frequently small or nonexistent, but remarkable exceptions to this rule are observed. Translocations discovered through unbalanced offspring were found to belong to different risk groups with the exception of the no risk group. Individual risk estimates have to be performed as a basis of genetic counselling before or during pregnancy so that parents with reciprocal translocations can make their choices regarding the available options.

Correlation of Morphological FAB Classification and Immunophenotyping: Value in Recognition of Morphological, Cytochemical and Immunological Characteristics of Mixed Leukaemias

Correlation between the FAB classification and immunophenotype was studied in 169 consecutive adult patients with acute leukaemia (AL). The lineage of leukaemic cells could be determined in the majority of cases, whereas 3 patients (1.8%) remained unclassified. In 22 out of 71 patients (31%) with acute myeloid leukaemia (AML) FAB M1 and M2 types, and in 5 out of 16 patients (31%) with chronic myeloid leukaemia (CML) in myeloid blast crisis, leukaemic cells did not express myeloid lineage-related markers, indicating asynchronous expression of cell markers in a substantial proportion of patients. Flow cytometric two-colour immunofluorescence revealed mixed AL immunophenotype in 6 out of 169 patients (3.4%). This group included five CD2+AML (5% of AML tested) and one undifferentiated AL expressing CD10(CALLA), CDw65(VIM-2). The former group included FAB M1, M2, M3 and M4 forms of AML with a single cell population, and an AML M2 patient with both cytochemically and immunologically two separate populations of leukaemic cells. This further illustrates the heterogeneity of the target cell(s) for leukaemogenesis and the level of differentiation of AML cells. However, there was no difference in the treatment response and the remission duration between AML patients and patients with mixed phenotype AML.

Chromosomal abnormalities and DNA image cytometry of haematological neoplasms in fine needle aspirates of lymph nodes

The current diagnostics of haematological neoplasms along with morphological analysis, immunophenotyping and molecular analysis inevitably includes cytogenetic analysis. In this work the possibility of cytomorphological subclassification of haematological neoplasms from lymph node fine needle aspirates was examined without depending upon the referential histological diagnosis and cytogenetic analysis. In addition, the feasibility of cytogenetic analysis of the material obtained by lymph node fine needle aspiration (FNA) was examined. By analysing the findings of cytogenetic analysis and DNA image cytometry, it was decided to examine the possibility of comparing the findings and supplementing diagnostic possibilities of these methods. In 15 cases cytological diagnoses and cytogenetic analysis of haematological neoplasms were performed on the material obtained by lymph node FNA. In 12 of 15 cases histological diagnosis was made separately. A good cytohistological correlation was available in 9 of 12 cases (75%). Cytomorphological diagnoses in 10 of 15 cases (76%) were confirmed by the finding of a specific chromosomal translocation. In two cases cytological diagnosis did not correlate with the histological diagnosis and was confirmed only with specific chromosomal translocations. The lymphocytes obtained by lymph node FNA were adequate material for cytogenetic analysis – in 15 of 18 (83%) cases mitoses in cell cultures were obtained. In 13 of 15 (87%) cases clonal chromosomal abnormalities were detected, whereas in 2 of 15 (13%) cases a normal karyotype was found. DNA image cytometry was performed on nine samples, whereas in six samples the material was not sufficient. Although a small number of samples was analysed in the cases with identical cytomorphological diagnoses, the analysed histograms regarding the DNA index values showed heterogeneity. In conclusion, a cell culture sampled by FNA of lymph nodes is an adequate method for the chromosomal analysis. The specific cytogenetic abnormality associated with cytological diagnosis provides an opportunity to make a definitive diagnosis and provides a powerful approach when reference diagnosis on biopsy material cannot be obtained.