Increased karyotype precision using fluorescence in situ hybridization and spectral karyotyping in patients with myeloid malignancies.

We studied seven patients with various malignant hematologic disorders using fluorescence in situ hybridization (FISH) and one of these patients with spectral karyotyping (SKY). With appropriate probes, the t(8;21) and inv(16) were confirmed in two patients and the karyotypic precision was increased in five others using FISH and SKY. Two of three patients with 12p rearrangements had a deletion of one TEL allele. Thus, these newer techniques are an important adjunct to accurate chromosome analysis in malignancy.

MLL is involved in a t(2;11)(p21;q23) in a patient with acute myeloblastic leukemia.

We describe a patient with acute myeloblastic leukemia (AML-M0) whose cells had a t(2;11)(p21;q23). Fluorescence in situ hybridization analysis with a probe for MLL showed that it was split, hybridizing to both the derivative 2 and 11 chromosomes. Nineteen other patients with 2p;11q translocations have been described; breakpoints in 14 of these are the same as in the case we describe. The phenotype of these patients is quite variable, with 14 patients having myelodysplastic syndrome which evolved to AML in six. Four patients had AML and two had acute lymphoblastic leukemia. MLL status has been studied in two other patients; one had MLL rearranged and one did not.

Translocation (2;3)(p13;q26) in two cases of myeloid malignancies. Acute myeloblastic leukemia (M2) and blastic phase of chronic myeloid leukemia.

Two cases of myeloid leukemias (acute [AML M2] and chronic [CMC]), blastic crisis, with identical t(2;3)(p13;q26) are described. These cases had some peculiarities: no significant decrease of blood thrombocyte count in the AML patient and high increase of blood thrombocyte count during blastic phase in the CML patient; dysplastic megakaryocytes in bone marrow and unfavorable course of the disease; and short remission (3 months) in AML and short chronic phase (8 months) in CML. Clinical and morphologic findings in patients with t(2;3)(p13;q26) resembled those in cases with 3q21q26 syndrome or with other chromosome rearrangements involving 3q21 or 3q26.

Blast cells in child and adult AML: comparative study of morphocytochemical, immunological and cytogenetic characteristics.

Bone marrow blast cells of 174 child and 188 adult patients with AML were examined and characterized in terms of their FAB type, immunological phenotype (102 children, 123 adults) and karyotype (69 children, 95 adults). The incidence of FAB variants of AML proved similar in children and adults. In patients under 15 and over 60, peroxidase activity in myeloblasts was lower than in middle-aged patients. Similar rates of HLA-Dr. Thy-1, CD11a, T-cell antigens, CD19, Gly-A and Eb antigens were found in cells of child and adult patients. The frequency of CD11b, CD38 and CD10 antigen expression on blast cells was higher in children than in adults. Abnormal blast karyotype was noted in 81.8% of children and 73.7% of adults. Translocation (8;21) was usually found in cases of M2 type (82%), significantly more frequently in children. predominantly in the group aged 6-10. t(15;17) was detected in all age groups only in M3 type of cells (86%). t(9;22) occurred more frequently in adults than in children; t(11q23) incidence rates were somewhat higher in children than in adults. Three cases of AML in children are described with deletion of chromosome 5 in their leukaemic cells. The data obtained indicate different biological characteristics of blast cells in children and adults. It is likely that haemopoietic cell involvement in children under 2 years and adult patients over 60 occurs at earlier stages than in middle-aged patients.

11q deletions in human colorectal carcinomas: cytogenetics and restriction fragment length polymorphism analysis.

Deletions and/or allelic losses of a portion of the long arm of chromosome 11 were discovered by cytogenetic and restriction fragment length polymorphism analyses in 23 of 39 (59%) informative cases of colorectal carcinoma. By comparing the patterns of loss of heterozygosity and chromosome rearrangements in different patients, we could map a common target region to 11q22-23. This region may contain a tumor suppressor gene, the inactivation of which may be involved in the development of tumors of the large intestine. The subgroup of malignancies with 11q alterations seemed to be enriched by tumors that were located in the rectum, that were Dukes' stage A, and that were well differentiated and mucin producing.

Translocations (17;20) in colorectal adenocarcinomas.

We describe new recurrent chromosome translocations (17;20) observed in 3 of 19 colorectal tumors. Two of them were identical: der(20)t(17;20)(q21;p12), resulting in the loss of 17(pter-->q21) and the third was a dicentric dic(17;20)(p11;p12). A similar dicentric was described previously in one tumor [1], but we report der(20)t(17;20)(q21;p12) for the first time.

Karyotype peculiarities of human colorectal adenocarcinomas.

The data of the chromosome abnormalities in 15 colorectal tumors are presented. Rearrangements of the short arm of chromosome 17, leading to deletions of this arm or its part were noted in 12 tumors; in 2 other cases, one of the homologs of pair 17 was lost. The losses of at least one homolog of other chromosomal pairs were also found: chromosome 18, in 12 out of 13 cases with fully identified numerical abnormalities; chromosome 5, in 6 tumors; chromosome 21, in 5 cases; chromosomes 4, 15, and 22, in 4 cases each. Additional homologs of pair 20 were observed in 6 tumors, extra 8q was found in 5 tumors, and extra 13q in 6 cases. Rearrangements of the short arm of chromosome 1 and the long arm of chromosome 11 characterized 6 tumors each. The data recorded in our series differ from the data of other authors in two respects: the high incidence of the loss of sex chromosomes and the rearrangements of the long arm of chromosome 9. X chromosomes were missing in 4 out of 7 tumors in females, and Y chromosomes were absent in 5 out of 8 tumors in males. The long arm of chromosome 9 was rearranged in 8 cases, in 5 of them the breakpoint being at 9q22. Cytological manifestations of gene amplification (double minutes or multiple microchromosomes) were noted in 6 tumors.

Chromosomal characteristics of malignant lymphoma.

Results of a cytogenetic and morphological study of 60 malignant lymphomas (ML) are presented. The most often observed chromosome abnormalities were rearrangements involving 14q32, 11q13, 11q21-23, 6q15, 6q21, 12p11-12, 17p11-12, and extra chromosomes 18, 3, 21 and 7. Translocations involving 14q32, leading to the appearance of marker 14q+, were noted in 41% of the tumors. Strict correlations between karyotype and morphology of ML were not seen. However, rearrangements of 11q were mostly found in low-grade tumors and markers 6q- in high-grade tumors. The absence of t(14;18), which is regarded to be the most common abnormality in ML, and an unusually high incidence of t(11;14) in our series confirm the uneven geographical distribution of ML with these translocations. Chromosome abnormalities in ML and acute lymphoblastic leukemia are compared.

A new specific chromosomal rearrangement, t(11;20)(p15;q11), in myeloblastic leukemia with maturation.

The translocation t(11;20)(p15;q11) was found as the sole acquired clonal chromosome abnormality in two patients with acute myeloid leukemia. The bone marrow morphology in both cases corresponded to the M2 subtype of the French-American-British (FAB) classification. None of the patients achieved complete remission, and both died less than 6 months after diagnosis. This particular translocation has not previously been reported in acute nonlymphocytic leukemia.

Chromosomes in acute nonlymphocytic leukemia.

The karyotype of leukemic cells was studied in 88 acute nonlymphocytic leukemia (ANLL) patients. Chromosome abnormalities were discovered in 78.4% of all patients and in 72.5% of the 69 patients studied before treatment. Characteristic abnormalities: translocations 8;21, 15;17, 9;22 or 6;9, rearrangements of 11q, gain of chromosomes 8 or 21, and loss or deletion of chromosomes 5 or 7 were detected in 56 of 69 patients with abnormal karyotypes. Translocation 8;21 was revealed in 27 patients; 20 of them had M2 FAB-form, four had M1, and three had M4. In patients with t(8;21) the incidence of complete remission was higher and the duration of first remission and survival longer than in patients with other abnormalities or with a normal karyotype.

Increased numbers of marrow basophils may be associated with a t(6;9) in ANLL.

We have characterized another subset of acute nonlymphocytic leukemia (ANLL) based on the cytogenetic and morphologic findings in a group of nine patients. Five patients had chromosomal analyses performed at the University of Chicago, two patients were studied at the All-Union Cancer Research Center in Moscow, and one patient each was studied at the University of Maryland and at Fairfax Hospital in Fairfax, Virginia. All nine patients had a reciprocal translocation involving the short arm of chromosome 6 and the long arm of chromosome 9 [t(6;9)(p23;q34)]. The patients, four males and five females, ranged in age from 5 to 51 years; the median age of 38 years is lower than that typically seen in ANLL. Only two of eight treated patients entered a complete remission. Classification of bone marrow morphology according to FAB Cooperative Group criteria revealed AML-M1 in one patient, AML-M2 in four, and AMMoL-M4 in three. One patient had refractory anemia with excess blasts (RAEB) which evolved to AML-M2. All bone marrow specimens showed severe myelodysplasia, with Auer rods present in seven of the nine cases. Of note was the particular prominence of bone marrow basophils (greater than 1%) in eight of the nine (89%) patients. Among 160 evaluable patients with ANLL de novo seen at the University of Chicago whose cells lacked a t(6;9), only five (3%) had greater than 1% basophils in the marrow aspirates. It is of interest that the breakpoint in 9q involves the same chromosomal band as that in the t(9;22) observed in chronic myelogenous leukemia (CML), in which increased basophils are a prominent feature. Thus, the association of the t(6;9) with increased bone marrow basophils in ANLL may provide additional insight into the chromosomal location of genes regulating the production and/or maturation of basophils.

Chromosomal rearrangements with a common breakpoint at 6p23 in five cases of myeloid leukemia.

Rearrangement of the short arm of chromosome 6 with a breakpoint at 6p23 was found in five patients with myeloid leukemia. Three of them had different morphological variants of AML (M2, M3, M4) and two blastic crisis of Ph1 negative and Ph1 positive CML. Identical translocation, t(6;9)(p23;q34), was revealed in two patients. One of them had AML (M2), the other blastic crisis of Ph1 negative CML. The blast cells of the last patient were morphologically similar to those in the M2 variant of AML. Translocation (6;9)(p23;q34) was also detected in two AML patients of Rowley and Potter (1976). The role of the breakpoint at 6p23 in myeloid malignancies needs further investigation.

Correlations between the clinical course, characteristics of blast cells, and karyotype patterns in chronic myeloid leukemia.

Results of chromosome studies of blood and bone marrow cells from 101 patients with Ph1 positive chronic myeloid leukemia (CML) confirm the assumptions that clinical and morphologic manifestations of the disease correlate with karyotype peculiarities of leukemia cells. Several variants of the clinical course of CML may be distinguished. One is the variant with a short chronic phase and a comparatively long terminal phase. In blastic crisis the blast cells are peroxidase negative and do not possess cytoplasmic inclusions. Acute transformation occurs without any additional chromosome damage. The second, more common form is less severe because of longer chronic phase but it has a short and grave acute stage. The blast cells present definite signs of myeloid differentiation, they have basophilic or neutrophilic cytoplasmic granules and are peroxidase positive. Marker i(17q) often combined with trisomy 8 is a characteristic chromosome abnormality in the terminal stage of this variant. The third type has an extremely long chronic phase but ends in a rapidly progressing severe and resistant to therapy "lymphoid" blastic crisis. Blast cells have typical "lymphoid" morphology, they are peroxidase negative and contain granular PAS positive substance. Various additional chromosome changes appear in the terminal stage. Future studies of a larger series of patients may possibly reveal more CML variants.

Chromosomal marker 20q- in cases of osteomyelosclerosis and CML.

Two male patients with myeloproliferative disorders (osteomyelosclerosis in one and CML in the other) were found to have a chromosomal marker 20q- in blood cells (unstimulated short time cultures). Marked erythropoietic disturbances were not revealed in these cases. The specificity of the 20q- marker for red cell disorders is discussed.

Chromosomes in acute leukemia.

The karyotype of leukemic cells of 78 acute leukemia patients (37 ANLL, 34ALL, and 7 of unknown type) was studied by means of G-banding. Chromosomal abnormalities were found in 50 patients (72%). Chromosomes 8,21,5,7,11, and 19 were preferentially involved in the abnormalities, both in ANLL and in ALL. A high incidence of the characteristic rearrangement t(8;21) was noted in AML: (in 6 of 22 AMP patients). An identical reciprocal translocation--t(4;11)--was seen in 4 out of 34 ALL patients.

Chromosome abnormalities and clinical and morphologic manifestations of chronic myeloid leukemia.

Forty cases of chronic myeloid leukemia (CML) were studied and subgroups of cases with similar chromosomal abnormalities in terminal stage were defined. Certain correlations were observed between the type of chromosomal changes, and clinical and morphologic manifestations of the disease: (1) It seems that, in cases without any karyotype changes other than translocation (9;22), the terminal stage is longer and milder than in cases with additional chromosomal abnormalities; (2) cases with marker i(17q) are clinically and morphologically rather uniform and are characterized by distinct signs of myeloid differentiation of blast cells, absent in other cases; (3) in cases with various atypical chromosomal abnormalities, the course of the terminal stage is the most rapid and grave. The blast cells differ from myeloblasts and resemble lymphoid elements.

Karyotype peculiarities of malignant lymphomas.

Karyotypes of 30 malignant lymphomas were studied with the aid of G-banding. Frequent occurrence of rearranged chromosomes 14 and 11 was noted. In several tumors, identical acrocentric markers, appearing after translocation of the long arm of chromosome 11 on the long arm of chromosome 14, were revealed. Other common karyotype abnormalities in lymphomas were trisomy 3 and trisomy 18. The chromosomes preferentially involved in karyotype abnormalities of the malignant lymphomas are mostly not altered in other hemoblastoses.

Certain patterns of karyotype evolution in chronic myelogeneous leukaemia. Chromosome abnormalities in CML.

The study of chromosome banding pattern of leukaemic cells in 15 patients with CML revealed t(9;22) in all cases. Similar additional chromosome abnormalities were observed in the terminal stage of the disease in 5 of 9 patients with aneuploid cell lines. The most frequent abnormalities were i(17q) and trisomy 8. The regularities of karyotype evolution in the terminal stage of CML are discussed.

Marker chromosome 14q+ in two non-Burkitt lymphomas.

Marker chromosome 14q+, similar to the specific marker of the Burkitt lymphoma, was revealed in all malignant blood cells of a patient with generalized lymphosarcoma, in all lymph node cells, and in a part of the blood cells of a patient with chronic lymphocytic leukaemia. Possible causes of this similarity are discussed.