Trisomy 10 in acute myeloid leukemia: three new cases

Hyperostosis - an unusual radiographic presentation of Myelodysplastic Syndrome transformed to Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is also referred to non-lymphocytic leukemia in the literature. It comprises about 15% of the childhood leukemia. There are multiple subtypes of AML from M0-M7 with approximately 45% of the cases being M0-M2 and the remaining subtypes being rare. The definitive diagnosis relies on bone marrow biopsy showing bone marrow infiltration with leukemic cells. We describe a rare radiographic presentation of myelodysplastic syndrome (MDS) transformed to AML in an 8 month old boy who presented with a orbital wall fracture, periosteal reaction, and mixed lytic and sclerotic lesions.

Direct evidence for cooperating genetic events in the leukemic transformation of normal human hematopoietic cells

Although genetic abnormalities associated with hematological malignancies are readily identified, the natural history of human leukemia cannot be observed because initiating and subsequent transforming events occur before clinical presentation. Furthermore, it has not been possible to study leukemogenesis in vitro as normal human cells do not spontaneously transform. Thus, the nature and sequence of genetic changes required to convert human hematopoietic cells into leukemia cells have never been directly examined. We have developed a system where the first step in the leukemogenic process is an engineered disruption of differentiation and self-renewal due to expression of the TLS-ERG oncogene, followed in some cases by overexpression of hTERT. In two of 13 experiments, transduced cells underwent step-wise transformation and immortalization through spontaneous acquisition of additional changes. The acquired karyotypic abnormalities and alterations including upregulation of Bmi-1 and telomerase all occur in acute myeloid leukemia (AML), establishing the relevance of this system. One resultant cell line studied in depth exhibits cellular properties characteristic of AML, notably a hierarchical organization initiated by leukemic stem cells that differentiate abnormally. These findings provide direct evidence for multiple cooperating events in human leukemogenesis, and provide a foundation for studying the genetic changes that occur during leukemic initiation and progression.

Classic and Molecular Cytogenetic Analyses Reveal Chromosomal Gains and Losses Correlated with Survival in Head and Neck Cancer Patients

Purpose: Genetic biomarkers of head and neck tumors could be useful for distinguishing among patients with similar clinical and histopathologic characteristics but having differential probabilities of survival. The purpose of this study was to investigate chromosomal alterations in head and neck carcinomas and to correlate the results with clinical and epidemiologic variables.

Experimental Design: Cytogenetic analysis of short-term cultures from 64 primary untreated head and neck squamous cell carcinomas was used to determine the overall pattern of chromosome aberrations. A representative subset of tumors was analyzed in detail by spectral karyotyping and/or confirmatory fluorescence in situ hybridization analysis.

Results: Recurrent losses of chromosomes Y (26 cases) and 19 (14 cases), and gains of chromosomes 22 (23 cases), 8 and 20 (11 cases each) were observed. The most frequent structural aberration was del(22)(q13.1) followed by rearrangements involving 6q and 12p. The presence of specific cytogenetic aberrations was found to correlate significantly with an unfavorable outcome. There was a significant association between survival and gains in chromosomes 10 (P = 0.008) and 20 (P = 0.002) and losses of chromosomes 15 (P = 0.005) and 22 (P = 0.021). Univariate analysis indicated that acquisition of monosomy 17 was a significant (P = 0.0012) factor for patients with a previous family history of cancer.

Conclusions: The significant associations found in this study emphasize that alterations of distinct regions of the genome may be genetic biomarkers for a poor prognosis. Losses of chromosomes 17 and 22 can be associated with a family history of cancer.

Acute myeloid leukemia with concomitant trisomies 4 and 10: a distinctive form of myeloid leukemia?

The occurrence of trisomy 4 or trisomy 10 as the sole chromosomal abnormality in acute myeloid leukemia (AML) is very rare, the reported frequency being less than 1%. We describe two cases of AML-M2 with concomitant trisomy 4 and trisomy 10, a hitherto undescribed phenomenon. They showed two unusual features, including immunoreactivity for CD56 and a short-lived but rapidly progressive myelodysplastic phase preceding the appearance of frank leukemia. These findings raise the possibility that AML with concommitant trisomy 4 and trisomy 10 may constitute a distinctive subtype of AML.