Biomedical subjects
Publications and source records attributed to C Mecucci.
We describe a case of Burkitt-type acute lymphoblastic leukemia (L3 according to the classification FAB) with a variant t(2;8)(p12;q24) and additional chromosomal abnormalities at diagnosis. The karyotype was 47,X,Xq+,t(2;8)(p12;q24),7q+,12p+,+mar. The literature on chromosome rearrangements associated with t(2;8) in L3 leukemias has been reviewed.
Cytogenetic studies were performed on 25 chronic myelogenous leukemia patients aged between 6 mo and 19 yr. Of these, 14 presented with the adult form and 11 with the juvenile form of the disease. In patients with the adult type, 12 of 14 had a Ph chromosome and additional anomalies appearing during blastic transformation. In patients with the juvenile form, 6 of 11 had a monosomy 7 and a short survival time (median 10 mo). Salient features of these patients, as well as a survey of the pertinent literature on the subject, are presented in this paper.
The effect of a PHA-conditioned medium was tested on a population highly enriched in hairy cells obtained from spleens of patients with hairy cell leukemia. Under PHA-CM treatment hairy cells adhered to both plastic and glass and spread assuming a typical stellate shape, without changing their enzymatic and antigenic properties. Provided PHA-CM was present, stellate adherent hairy cells remained viable in culture for several months. Mononuclear splenic cells from patients with various hematological disorders never showed similar phenotypic modifications after PHA-CM treatment.
A variant insertion (10p; 11q) preceded by a paracentric inversion of the long arm of chromosome 11, inv(11)(q12q23), has been found in a patient with ANLL-M5a. The association of 11q abnormalities involving the breakpoint 11q23 with acute monocytic leukemia is confirmed.
A t(1;3)(p36;q21) translocation was found in bone marrow samples of two patients with hematologic disorders. One patient had a myelodysplastic syndrome evolving into acute nonlymphocytic leukemia (ANLL) M1 and the second patient had ANLL-M6 secondary to treatment for Hodgkin's disease. Because myelodysplastic syndromes and secondary leukemia are stem cell disorders, the t(1;3)(p36;q21) appears to be a chromosome abnormality in malignant myeloid stem cells.
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Serial chromosome investigations performed in untreated myelodysplastic syndromes (MDS) revealed that: multiple chromosomally unrelated cell populations may emerge during the course of the disease; chromosome changes of the clonal type may disappear or become undetectable, and may or may not reappear during further evolution. The former of these phenomena was found in four cases and was consistently associated with clinical-haematological progression of the disease to a more malignant form, including acute leukaemia. The second was apparently unrelated to clinical and haematological changes in the evolution pattern. These observations are in favour of the hypothesis that MDS evolve as a multistep process in which several events, including the acquisition of sometimes unrelated chromosome changes determine the progression of the disease.
An identical translocation between the long arm of chromosome no. 1 and the short arm of chromosome no. 15 was found in two unrelated patients with refractory anaemia type I, according to the FAB classification of myelodysplastic syndromes. In the first patient the typical translocation was associated with anomalies commonly found in preleukaemic states, i.e. a 5q- and a 20q- chromosome. Furthermore, in both patients the long arm of chromosome no. 1 was trisomic. Cytogenetic follow-up in the second patient demonstrated a proliferative advantage of the cells bearing a t(1;15) translocation over the cells with trisomy 8 as well as over normal cells. This karyotypic evolution, however, was not accompanied by a transformation of the haematological disorder into acute leukaemia.
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We report the case of a 19-year-old girl in whom a Ph1-positive chronic myeloid leukemia was diagnosed 10 months after an episode of infectious mononucleosis. Clinical and cytogenetical follow-up demonstrated the appearance of a variant Philadelphia chromosome translocation t(7;9;22) during a blastic crisis characterized by early B-lymphoid elements. The association between the t(7;9;22) variant Philadelphia and the lymphoid blast cells is emphasized, and the importance of Epstein-Barr virus (EBV) infection in the pathogenesis of the disease in this case is discussed.
We have observed three patients with t(4;11)(q21;q23) among the 50 cases of ALL studied. Two were classified as L1 and the third as L3. We comment on the relationship between the morphologic classification of leukemias and the association with a t(4;11).
We present four patients with acute nonlymphocytic leukemia, one M2 and three M4 French-American-British (FAB) types and one patient with refractory anemia with excess of blasts in transformation who at diagnosis had trisomy of chromosome 4 as the primary karyotypic anomaly. This chromosome anomaly probably defines a previously undescribed subset of acute nonlymphoid leukemias. Hematologic characteristics commonly found in these patients were dysplastic features of all bone marrow lineages, suggesting that trisomy 4-associated disorders involve the early myeloid hematopoietic stem cell.
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A case of typical T-acute lymphoblastic leukemia (T-ALL) is reported in which, at diagnosis, 100% of bone marrow metaphases showed a Philadelphia (Ph) translocation, t(9;22). These cells completely disappeared following chemotherapy. The significance of the Ph chromosome in T and B leukemic cells is discussed.
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Cytogenetic studies on four patients with T-cell lymphomas are reported. In all four the short arm of chromosome No. 6 (6p) was abnormal. In three cases it was involved in a translocation, and in one there was a deletion of the terminal part: del(6)(p23-24). One of the translocations could be identified as a t(2:6)(q24;p24). Identification was not possible in the others. These 6p anomalies were associated with complex structural and numerical abnormalities of other chromosomes in three out of four cases. In three patients chemo- and/or radiotherapy administration preceded cytogenetic investigations.
A deletion of the long arm of chromosome #5 (5q-) occurs nonrandomly in human malignancies. As a rule, the deletion is interstitial; the distal breakpoint by conventional techniques is usually in band q32, the proximal breakpoints in q12 or q14. Variant breakpoints occur in less than 10% of all cases. As the sole anomaly, 5q- is characteristically found in refractory anemia with or without excess of blasts. It can occur as the sole anomaly in de novo or secondary acute nonlymphocytic leukemia, but is usually accompanied in those disorders by other chromosome changes that are also nonrandomly distributed. In addition, it can be found in lymphoproliferative disorders, and occasionally, also in solid tumors. The 5q- myelodysplastic syndrome typically occurs in older age groups, particularly in females. Characteristic features are macrocytic anemia, normal or elevated platelets in the presence of megakaryocytic anomalies, and a mild clinical course. In cases with 5q- only, transformation into ANLL occurs rarely. Additional chromosome anomalies and male sex are prognostically unfavorable signs. Sex ratio is also at the disadvantage of females in de novo 5q- ANLL, and the latter disorder can occur without being preceded by a myelodysplastic phase. A myelodysplastic phase usually precedes 5q- secondary leukemia, in males as well as in females, and additional chromosome anomalies, especially of chromosome #7, are almost invariably present in those cases. We conclude that 5q- is the most frequently occurring single chromosome anomaly in secondary leukemia. Furthermore, the resemblance between de novo and secondary 5q- MDS and ANLL is striking; clinically, as well as cytogenetically, they are indistinguishable, suggesting that all de novo cases may be due to environmental (chemical) carcinogens. Response to treatment and prognosis are very poor with current therapeutic regimens in de novo as well as in secondary 5q- ANLL. Morphologically, these ANLLs fall into all FAB categories. There is considerable evidence to show that the 5q- anomaly occurs in a myeloid precursor stem cell. The occasional occurrence in lymphoid malignancies, of B cell as well as T cell type, suggests that, as in Ph-positive disorders, a common progenitor stem cell may be affected in 5q- also. The 5q- lymphoid malignancies, however, are much more rare; it is not clear at the present time whether or not a 5q- counterpart of Ph-positive ALL exists, and mixed lymphoid-myeloid 5q- disorders have not yet been documented.(ABSTRACT TRUNCATED AT 400 WORDS)
Two patients, possibly exposed to toxic agents, presented with a myelodysplastic syndrome (MDS) and a t(1;7) in bone marrow metaphases. This observation confirms the occurrence of this characteristic chromosome anomaly in MDS and its possible induction by environmental agents. It is hypothesized that this t(1;7) MDS may not be confined to a particular geographical area but that, in the past, it may have been overlooked in the absence of optimal banding, which is obviously necessary to identify the anomaly.