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

How breast cancer chemotherapy increases the risk of leukemia: Thoughts about a case of diffuse large B-cell lymphoma and leukemia after breast cancer chemotherapy

The latest studies suggest that prophylactic chemotherapy or adjuvant chemotherapy for early stage breast cancer may increase the leukemia risk in patients. For patients with a low risk for breast cancer recurrence, physicians who make the choice for adjuvant therapy should consider the risk of its long-term side effects. Is the occurrence of lymphatic system cancer and leukemia after breast cancer treatment associated with chemotherapy? Can these types of leukemia be classified as therapy-related leukaemias? We believe that there may be correlations between any diseases, butwe cannot rush to conclusions or dismiss a correlation because we understand little about the diseases themselves.In this paper, we present a case of secondary diffuse large B-cell lymphoma and leukemia in patients after breast cancer chemotherapy, it is undeniable that this is a special event. For two distinct tumouroccurrences at different times, we cannot give a clear explanation because of thechanges in the genes that might link them together and we hope to attract the attention of other clinicians.

Nuclear envelope-limited chromatin sheets (ELCS) and heterochromatin higher order structure

The interphase nucleus and nuclear envelope can acquire a myriad of shapes in normal or pathological cell states. There exist a wide variety of indentations and invaginations, of protrusions and evaginations. It has been difficult to classify and name all of these nuclear shapes and, consequently, a barrier to understanding the biochemical and biophysical causes. This review focuses upon one type of nuclear envelope shape change, named "nuclear envelope-limited chromatin sheets" (ELCS), which appears to involve exaggerated nuclear envelope growth, carrying with it one or more layers of approximately 30 nm diameter heterochromatin. A hypothesis on the formation of ELCS is proposed, relating higher order heterochromatin structure in an interphase nucleus, nuclear envelope growth, and nuclear envelope-heterochromatin interactions.

Distinct cytogenetic and clinicopathologic features in acute myeloid leukemia after occupational exposure to pesticides and organic solvents

BACKGROUND

To study the correlation of environmental exposure to potentially mutagenic agents and the clinicopathologic picture in acute myeloid leukemia (AML), clinical features, morphologic characteristics, immunophenotype, and cytogenetics were studied in 59 patients with newly diagnosed AML.

METHODS

Based on interviews on occupational hazards and hobbies showing prolonged contact with pesticides (18 patients) and organic solvents (7 patients), 25 patients were categorized as "exposed". Thirty-four patients were categorized as "unexposed,", based on anamnestic findings.

RESULTS

Light microscopic studies showed myelodysplasia involving multiple cell lineages in all assessable patients with professional exposure to pesticides and organic solvents, whereas morphologic aberrations of the non-blast cell population were confined to a minority of cells in unexposed patients. These findings were confirmed by electron microscopic studies in 31 patients. Immunologic analysis showed the presence of a minor megakaryoblastic component in six exposed patients and showed positive findings for the CD34 stem cell marker in 85% of exposed patients, a figure significantly higher as compared with that for unexposed subjects. Cytogenetic studies confirmed the frequent occurrence of 5q and/or 7q aberrations in patients occupationally exposed (10 of 25 cases). Other recurring chromosome aberrations in the exposed group were 17p-, trisomy 11q, and translocation of 16q, 6p, 7p, and 11p, whereas the classic AML-specific translocations (i.e., t[15;17]; t[8;21]) were detected only in unexposed subjects. Conventional chemotherapy achieved complete remission in 1 of 19 exposed patients, as opposed to 14 of 29 unexposed patients, with a median survival of 2 months in the former group and 8 months in the latter.

CONCLUSIONS

Taken together, these findings document that AML in patients professionally exposed to toxic substances may represent a distinct cytogenetic and clinicopathologic entity. The clinicobiologic characteristics in these exposed patients are similar to the features of AML arising in patients with prior chemotherapy for another tumor, thus suggesting that similar transformation pathways may underlie leukemogenesis induced by cytotoxic drugs and by environmental exposure to some pesticides or organic solvents.

Morphologic, immunologic and cytogenetic studies in erythroleukaemia: evidence for multilineage involvement and identification of two distinct cytogenetic-clinicopathological types

Clinical features, as well as morphology, immunophenotype and cytogenetics were retrospectively studied in 20 patients with an original diagnosis of erythroleukaemia (EL) reclassified according to the FAB criteria. Fifteen patients had de novo EL, five patients had therapy-related EL. Myelodysplasia preceded the onset of EL in eight cases and myelodysplastic features involving multiple haemopoietic lineages were observed at leukaemia presentation in all cases. Immunologic findings confirmed multilineage involvement, showing sub-population of cells expressing platelet-associated markers in more than 50% of cases tested and the presence of a myelomonocytic component, besides glycophorin A-positive cells. Cytogenetically, major karyotype aberrations (MAKA), defined by the presence of three or more aberrant events in the same clone, were observed in 14 cases, minor karyotype aberrations (MIKA) were observed in four cases and normal karyotype in two cases. No differences in the cytological-cytogenetic picture of our patients with de novo EL, and with therapy-related EL were found suggesting that aetiological factors and/or pathogenetic mechanisms common to EL and secondary leukaemia may exist. All patients with MAKA had leftward shift of erythropoiesis with proerythroblasts and basophilic erythroblasts usually representing more than 50% of all erythroid cells. In patients with MIKA or normal karyotype, maturatio of erythroid cells, though morphologically abnormal, was quantitatively preserved and early erythroblasts never exceeded 25% of erythroid cells. Clinically, the haemoglobin level at presentation, as well as in the proportion of patients achieving complete remission after chemotherapy, appeared to be lower in the maturation arrest-MAKA group as compared to the preserved maturation-MIKA/normal karyotype group. Median survival was shorter in the former group (3.5 months) than in the latter (median 13 months). Morphologic-immunologic-cytogenetic studies thus allow for the identification of two distinct cytogenetic-clinicopathological types of EL.

Acute leukaemia with t(4;11) in patients previously exposed to carcinogens

We report three cases of acute leukaemia with t(4;11) (q21;q23), one of them of undifferentiated and the other two of lymphoid phenotype, occurring after adjuvant radiochemotherapy for breast cancer (two cases) or occupational exposure to radiation (one case). Although the myeloid phenotype and characteristic chromosomal anomalies usually observed in secondary leukaemia were lacking, our observations raise the possibility of causal relationship between exposure to carcinogens and the occurrence of a leukaemia with t(4;11).

The iatrogenic leukaemias induced by radio- and/or chemotherapy

A short review, limited to recently published series of data, has been compiled on the 'therapy-induced' secondary malignancies. Their frequency, peak of incidence, haematological and clinical criteria, the influence of age, treated primary disease, choice of drug(s) and modality of prescription and the role of genetic and environmental factors are analyzed. The risk varies between 0.6 and 20.5% after different treatment forms. Some suggestions for the choice of treatment of chronic malignant disorders, and for the design of future epidemiological studies are given.

Allogeneic bone marrow transplantation in a patient with acute myeloid leukemia secondary to Hodgkin's disease

A patient with Hodgkin's disease entered complete clinical remission by combination radiochemotherapy. He developed dyshematopoiesis 1.5 years later and an overt acute nonlymphocytic leukemia 3 years after diagnosis. A complete remission was achieved following 2 courses of intensive polychemotherapy. Four months later, while still in remission, he underwent an allogeneic bone marrow transplantation (BMT) from an HLA-identical sister. Mild chronic graft versus host disease of the skin occurred 3 months after BMT, and now the patient has been in complete remission of leukemia for over 2 years. This appears to be a unique case of prolonged remission of a leukemia secondary to an intensively treated Hodgkin's disease.