Imaging of spindle cell lipoma.

AIM: To review the evaluation, diagnosis, and treatment of spindle cell lipoma (SCL) with emphasis on the location of these tumours and the spectrum of magnetic resonance imaging (MRI) and computed tomography (CT) appearances. MATERIALS AND METHODS: The MRI and CT findings of 27 histopathologically proven SCLs were evaluated retrospectively. Imaging features evaluated included margins, percentage visible fat, MRI signal characteristics, oedema, and contrast enhancement patterns. RESULTS: Patient ages ranged from 18 to 80 years with an average age of 56.5 years. Men were affected twice as frequently as women (M=18, F=9). SCLs ranged in size from 2 to 10 cm, with an average greatest dimension of 5.5 cm. Five lesions (19%) contained no visible fat on CT or MRI, and the leading differential diagnosis of high-grade soft-tissue sarcoma diagnosis was suggested by referring surgeons. Five lesions (19%) had <50% fatty areas, nine lesions (52%) demonstrated >50% but <90% fat at MRI or CT. Only three of 25 lesions (12%) had an appearance of a typical lipoma on unenhanced MRI sequences. All SCLs that were imaged with contrast medium (n = 18) demonstrated some degree of enhancement, with eight (44%) showing marked enhancement, four (22%) showing moderate, and six (33%) minimal enhancement. CONCLUSION: SCLs have considerably variable imaging appearances and may have minimal or no visible fat at MRI or CT. Imaging features may make it difficult to distinguish this benign tumour from a potentially higher-grade malignant tumour.

Three-dimensional analysis versus goniometric measurement of total active elevation in normal subjects.

BACKGROUND: Multiple planes of motion have been reported for shoulder elevation performed by visual inspection with a goniometer. It is typically measured by a clinician who is standing or sitting at the side of the patient. Instead, accurate assessment of shoulder elevation must be performed by using a plane of reference that is perpendicular to the plane of motion being measured. METHODS: Three repetitions of humeral elevation in the sagittal, scapular, and coronal planes were performed in a random order and measured by goniometry and three-dimensional (3D) electromagnetic sensors. A guide bar was used to control the initial plane of motion for the sagittal and coronal planes. The plane of motion at 90° and at peak elevation was recorded for each of the 3 defined planes. A goniometer was used to measure the range of maximal elevation performed in each plane, for each subject, by visual inspection. RESULTS: The 3D data revealed that subjects consistently moved toward scaption as the extremity moved above 90° of elevation, regardless of the initial plane of motion. Significant differences were seen in the goniometric data for the plane of motion at 90° (P = .00) in flexion, abduction, and scaption. Goniometric measurements revealed greater maximum elevation angles in comparison to the 3D kinematic measurements. CONCLUSIONS: Maximal glenohumeral elevation occurred near the plane of the scapula in all subjects, regardless of the plane in which elevation was initiated. Goniometric measurement of total elevation resulted in greater range of motion measurements than actually occurred because the observer was not routinely positioned in a plane perpendicular to the plane of actual elevation of the upper extremity.

A phase I study of decitabine with pegylated interferon α-2b in advanced melanoma: impact on DNA methylation and lymphocyte populations.

BACKGROUND: Melanoma cell lines treated with decitabine show upregulation of cancer antigens, and interferon-α upregulates MHC Class I antigens in cancer cells, leading to enhanced T-cell recognition and T-cell mediated tumor apoptosis. We evaluated the synergy between the hypomethylating effects of decitabine and the immunomodulatory effects of interferon in a combination regimen administered to advanced melanoma patients in a phase 1 trial. METHODS: Patients with one prior systemic therapy were eligible. Using a modified 3 + 3 design, patients received escalating doses of decitabine and pegylated interferon α-2b (PEG-IFN) during every 28-day treatment cycle. Global DNA methylation was measured on days 1 and 5 of cycles 1 and 3. Cytokine profiling and quantification of T-cell subpopulations by FACS were performed at baseline and cycle 3. RESULTS: Seventeen patients were assigned to one of four dose levels. Decitabine 15 mg/m2/d + PEG-IFN 3 µg/kg was the maximum tolerated dose (MTD). Grade 3/4 cytopenias were seen across all dose levels: anemia (1), neutropenia (7), and thrombocytopenia (2). One patient remained progression-free for 37 weeks. The other 16 patients progressed at or before 12 weeks. Median overall survival was 39 weeks. Hypomethylation was seen at all dose levels. Due to treatment-induced lymphocytopenia, absolute changes in T-cell populations post-treatment were too small to be meaningfully interpreted. CONCLUSIONS: The response to this combination regimen was characterized by significant myelosuppression, particularly neutropenia. Although disappointing efficacy and slow accrual led to early closure of the trial, hypomethylation showed pharmacodynamic evidence of a therapeutic effect of decitabine at all dose levels.

Phase I trial of dasatinib and ixabepilone in patients with solid tumors.

PURPOSE: Dasatinib is an oral tyrosine kinase inhibitor (TKI) of BCR-ABL and SRC family and ixabepilone is an epothilone B analog. Synergistic activity has been reported when combining dasatinib with chemotherapy. This study was conducted to determine the dose-limiting toxicities (DLTs) and the maximum tolerated doses (MTDs) for this combination. PATIENTS AND METHODS: Patients with metastatic solid tumors who progressed on standard therapy received dasatinib orally daily and ixabepilone IV every 3 weeks at escalating doses using 3 + 3 design. An expansion cohort was studied after reaching the MTD. Pharmacokinetic studies were performed. RESULTS: Nineteen patients were enrolled. No DLTs were observed at dose level (DL) 1 (dasatinib 100 mg and ixabepilone 30 mg/m(2)). At DL 2 (dasatinib 100 mg and ixabepilone 40 mg/m(2)), one patient had multiple DLTs. At DL 3 (dasatinib 150 mg and ixabepilone 40 mg/m(2)), the first patient developed grade 3 AE during cycle 2, the second patient had a DLT and a grade 3 AE during cycle 2. The accrual to DL 3 was halted without reaching the maximally administered dose (MAD) and MTDs were determined to be dasatinib 100 mg and ixabepilone 40 mg/m(2) (DL 2). One patient had a partial response and 12 patients stable disease as their best response. Fourteen patients came off study due to toxicities. CONCLUSION: The combination of dasatinib and ixabepilone showed modest clinical activity with doses 100 mg orally daily and 40 mg/m(2) IV every 3 weeks, respectively. Treatment related toxicities were seen frequently.

Genome-wide DNA methylation analysis identifies promoter hypermethylation in canine malignant melanoma.

Canine malignant melanoma is a common cancer with a high mortality rate. Although previous studies have evaluated various aspects of this tumour, the exact mechanism of tumourigenesis remains unknown. Epigenetic mechanisms, such as DNA methylation, have recently gained attention as aetiological factors for neoplasia in humans. This study aimed to analyse genome-wide DNA methylation patterns in canine malignant melanoma based on next-generation sequencing data. A total of 76,213 CpG sites, including 29,482 sites in CpG islands (CGIs), were analysed using next-generation sequencing of methylation-specific signatures, obtained by sequential digestion with enzymes, to compare normal oral mucosal samples from four healthy dogs, four canine melanoma cell lines (3 oral cavity and 1 skin), and five clinical samples of oral canine melanoma. Malignant melanoma showed increased methylation at thousands of normally unmethylated CpG sites in CGIs and decreased methylation at normally methylated CpG sites in non-CGIs. Interestingly, the promoter regions of 81-393 genes were hypermethylated; 23 of these genes were present in all melanoma cell lines and melanoma clinical samples. Among these 23 genes, six genes with "sequence-specific DNA binding" annotation were significantly enriched, including three Homeobox genes-HMX2, TLX2, and HOXA9-that may be involved in the tumourigenesis of canine malignant melanoma. This study revealed widespread alterations in DNA methylation and a large number of hypermethylated genes in canine malignant melanoma.

Dynamic changes in DNA methylation patterns in canine lymphoma cell lines demonstrated by genome-wide quantitative DNA methylation analysis.

DNA methylation is the conversion of cytosine to 5-methylcytosine, leading to changes in the interactions between DNA and proteins. Methylation of cytosine-guanine (CpG) islands (CGIs) is associated with gene expression silencing of the involved promoter. Although studies focussing on global changes or a few single loci in DNA methylation have been performed in dogs with certain diseases, genome-wide analysis of DNA methylation is required to prospectively identify specific regions with DNA methylation change. The hypothesis of this study was that next-generation sequencing with methylation-specific signatures created by sequential digestion of genomic DNA with SmaI and XmaI enzymes can provide quantitative information on methylation levels. Using blood from healthy dogs and cells obtained from canine lymphoma cell lines, approximately 100,000CpG sites across the dog genome were analysed with the novel method established in this study. CpG sites in CGIs broadly were shown to be either methylated or unmethylated in normal blood, while CpG sites not within CpG islands (NCGIs) were largely methylated. Thousands of CpG sites in lymphoma cell lines were found to gain methylation at normally unmethylated CGI sites and lose methylation at normally methylated NCGI sites. These hypermethylated CpG sites are located at promoter regions of hundreds of genes, such as TWIST2 and TLX3. In addition, genes annotated with 'Homeobox' and 'DNA-binding' characteristics have hypermethylated CpG sites in their promoter CGIs. Genome-wide quantitative DNA methylation analysis is a sensitive method that is likely to be suitable for studies of DNA methylation changes in cancer, as well as other common diseases in dogs.

Receptors for human gamma G globulin on human neutrophils.

Cell surface receptors for human gammaG antibodies directed against bacterial antigens were demonstrated on human neutrophils using an in vitro bacteriocidal-phagocytic assay. These results were confirmed by adherence of sensitized erythrocytes to monolayers of neutrophils or monocytes. Erythrocytes sensitized indirectly with antibacterial gammaG antibodies after passive sensitization with bacterial antigens adhered to both neutrophils and monocytes. Erythrocytes sensitized directly with conventional anti-D gammaG antibodies adhered only to monocytes, while those sensitized with the hyperimmune anti-CD gammaG antibody Ripley adhered to both monocytes and neutrophils. Adherence of anti-Rh or antibacterial gammaG antibodies to monocytes and neutrophils could be inhibited by whole gammaG, myeloma globulins of the gamma(1) or gamma(3) subclasses, or Fc fragments, but not by Fab fragment. These results indicate that receptors for the Fc portion of human gammaG antibodies exist on both neutrophils and monocytes, and that gammaG antibodies differ in their ability to attach to these two cell types. Differences in the behavior of the gammaG antibodies studied may be related to differences in the density of antibodies on the erythrocyte surface and receptors on the phagocytic cells.

A CpG island methylator phenotype in acute myeloid leukemia independent of IDH mutations and associated with a favorable outcome.

Genetic changes are infrequent in acute myeloid leukemia (AML) compared with other malignancies and often involve epigenetic regulators, suggesting that an altered epigenome may underlie AML biology and outcomes. In 96 AML cases including 65 pilot samples selected for cured/not-cured, we found higher CpG island (CGI) promoter methylation in cured patients. Expanded genome-wide digital restriction enzyme analysis of methylation data revealed a CGI methylator phenotype independent of IDH1/2 mutations we term AML-CGI methylator phenotype (CIMP) (A-CIMP+). A-CIMP was associated with longer overall survival (OS) in this data set (median OS, years: A-CIMP+=not reached, CIMP-=1.17; P=0.08). For validation we used 194 samples from The Cancer Genome Atlas interrogated with Illumina 450k methylation arrays where we confirmed longer OS in A-CIMP (median OS, years: A-CIMP+=2.34, A-CIMP-=1.00; P=0.01). Hypermethylation in A-CIMP+ favored CGIs (OR: CGI/non-CGI=5.21), and while A-CIMP+ was enriched in CEBPA (P=0.002) and WT1 mutations (P=0.02), 70% of cases lacked either mutation. Hypermethylated genes in A-CIMP+ function in pluripotency maintenance, and a gene expression signature of A-CIMP was associated with outcomes in multiple data sets. We conclude that CIMP in AML cannot be explained solely by gene mutations (for example, IDH1/2, TET2), and that curability in A-CIMP+ AML should be validated prospectively.

Chromatin remodeling gene SMARCA5 is dysregulated in primitive hematopoietic cells of acute leukemia.

We identified a subset of genes involved in chromatin remodeling whose mRNA expression changes in differentiating mouse erythroleukemia (MEL) cells. We furthermore tested their mRNA expression patterns in normal and malignant CD34+ bone marrow cells. SMARCA5, imitation switch gene homologue, was rapidly silenced during in vitro erythroid differentiation of MEL cells whereas it was up-regulated in CD34+ hematopoietic progenitors of acute myeloid leukemia (AML) patients. Moreover, SMARCA5 mRNA levels decreased in AML CD34+ progenitors after the patients achieved complete hematologic remission. We detected high levels of SMARCA5 mRNA in murine bone marrow and spleen and monitored its expression in these hematopoietic tissues during accelerated hematopoiesis following hemolytic anemia induced by phenylhydrazine. SMARCA5 expression levels decreased after the onset of accelerated erythropoiesis. Our data suggest that both in vitro and in vivo induction of differentiation is followed by down-regulation of SMARCA5 expression. In CD34+ AML progenitors over-expression of SMARCA5 may thus dysregulate the genetic program required for normal differentiation.

TRAIL (Apo2L) suppresses growth of primary human leukemia and myelodysplasia progenitors.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL, APO2L) has been shown to induce apoptosis in a number of tumor cell lines as well as in some primary tumors whereas cells from most normal tissues are highly resistant to TRAIL-induced apoptosis. We have studied the susceptibility of primary malignant and normal bone marrow hematopoietic progenitors to TRAIL-induced apoptosis. Extracellular domain of human TRAIL with N-terminal His(6) tag (His-TRAIL, amino acids 95-281) was produced in E. coli and its apoptosis-inducing ability was compared with the leucine-zipper containing TRAIL, LZ-TRAIL. Both variants of TRAIL had the same apoptosis-inducing ability. Clonogenic progenitor assays showed that His-TRAIL significantly reduced the number of myeloid colonies (CFU-GM) and clusters from patients with acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and myelodysplastic syndromes (MDS). His-TRAIL had no negative effect on the number of CFU-GM colonies and clusters derived from bone marrow cells of AML patients in complete remission, and lymphoma patients without bone marrow involvement, as well as those derived from normal cord blood cells. Moreover, we found that normal human stem cells treated with high doses of His-TRAIL maintain a repopulating potential when transplanted into NOD/SCID mice. To conclude, our data document that TRAIL does not affect normal human hematopoiesis but suppresses the growth of early primary leukemia and myelodysplasia progenitors.

Liver DNA methylation analysis in adult female C57BL/6JxFVB mice following perinatal exposure to bisphenol A.

Bisphenol A (BPA) is a compound released from plastics and other consumer products used in everyday life. BPA exposure early in fetal development is proposed to contribute to programming of chronic diseases like obesity and diabetes, by affecting DNA methylation levels. Previously, we showed that in utero and lactational exposure of C57BL/6JxFVB hybrid mice via maternal feed using a dose range of 0-3000µg/kg body weight/day resulted in a sex-dependent altered metabolic phenotype in offspring at 23 weeks of age. The most univocal effects were observed in females, with reduced body weights and related metabolic effects associated with perinatal BPA exposure. To identify whether the effects of BPA in females are associated with changes in DNA methylation, this was analyzed in liver, which is important in energy homeostasis. Measurement of global DNA methylation did not show any changes. Genome-wide DNA methylation analysis at specific CpG sites in control and 3000µg/kg body weight/day females with the digital restriction enzyme analysis of methylation (DREAM) assay revealed potential differences, that could, however, not be confirmed by bisulfite pyrosequencing. Overall, we demonstrated that the observed altered metabolic phenotype in female offspring after maternal exposure to BPA was not detectably associated with liver DNA methylation changes. Still, other tissues may be more informative.

Experimental hypertension in young and adult animals.

The susceptibility of immature and adult animals to various environmental factors often differs because the response of the young organism can only involve those regulatory mechanisms that are available at the particular stage of development. Increased sensitivity to certain (e.g., hypertensive) stimuli may be limited to a relatively short age period that is usually characterized by the maturation of some important physiological functions. High salt intake seems to influence the animals especially during the weaning period and prepuberty, in the course of which profound developmental changes of circulation, electrolyte metabolism, and neurohumoral regulation have been demonstrated. Indeed, salt-dependent forms of experimental hypertension are more severe when they are induced in immature animals. Moreover, substantial differences in hemodynamics, distribution of body fluids, and involvement of pressor and natriuretic agents indicate that the mechanisms of salt hypertension need not be the same in immature and adult animals. For this reason, increased attention should be paid to developmental factors in the study of induced forms of experimental hypertension.

A primate model of human postmenopausal hot flushes.

The hot flush is the only symptom specifically attributable to the menopause. Hot flushes appear to represent an episodic derangement of thermoregulation as a result of estrogen deficiency but the underlying physiological mechanisms are unknown. We have developed an animal model for the study of hot flushes. Two female monkeys (Macaca arctoides) were trained to accept monitoring of scalp cutaneous temperatures. After baseline temperature recordings were obtained both monkeys were ovariectomized. A few days after operation the previously stable scalp temperature changed to an undulating pattern with cycles lasting approximately 40-50 min. Ethinyl estradiol (20 micrograms orally or im) and (7 alpha,17 alpha)-17-hydroxy-7-methyl-19-nor-pregn-5(10)-en-20-yn-3-one (2.5 mg orally), a steroid with weak estrogenic, progestogenic, and androgenic properties, suppressed the characteristic undulating temperature pattern; this returned after withdrawal of replacement therapy. Clonidine (0.15 mg twice a day) suppressed the cyclic changes for 2 to 3 h. Domperidone and naloxone had no significant effect. This animal model may be useful for the investigation of alternative therapy for the management of menopausal flushes.

The efficacy of radiotherapy as postoperative treatment for desmoid tumors.

PURPOSE: The purpose of this study was to determine if radiotherapy is a beneficial adjuvant treatment after desmoid tumor resection. METHODS AND MATERIALS: A retrospective analysis was performed on 54 patients who underwent surgery without prior radiation at our institution between 1982 and 1998 to remove a desmoid tumor. Thirty-five patients had adjuvant radiation therapy after surgery, and 19 patients had surgery alone without immediate postoperative radiation. Sixteen of the 35 patients who underwent immediate postoperative radiation treatment had at least one prior resection before reoperation at our institution. Recurrence was defined as radiographic increase in tumor size after treatment. Follow-up interval (mean 39 months) and duration of local control were measured from the date of surgery at our institution. Potential prognostic factors for time to tumor progression were analyzed. RESULTS: Adjuvant treatment with radiation was the only significant prognostic factor for local control. The five-year actuarial local control rate was 81% for the 35 patients who underwent radiation in addition to surgery, compared to 53% for the 19 patients who underwent surgery alone (p = 0.018). For the patients who did not receive adjuvant radiation, only younger age at the time of surgery was associated with increased risk of failure (p = 0.035). Gross or microscopic margin status and number of prior operations were not detected as prognostic for local failure. For patients who did receive postoperative radiation, only abdominal location was associated with increased risk of failure (p = 0.0097). CONCLUSION: Radiation treatment as an adjuvant to surgery improved local control over surgery alone. Multiple operations before adjuvant radiation did not decrease the probability of subsequent tumor control. Radiation should be considered as adjuvant therapy to surgery if repeated surgery for a recurrent tumor would be complicated by a significant risk of morbidity.

Management of patients with thyroid carcinoma: application of thallium-201 scintigraphy and magnetic resonance imaging.

Thyroid carcinoma has the ability to concentrate radioiodine, an attribute that can be used both for detection of thyroid cells and for treatment. Unfortunately, however, radioiodine uptake is not observed in all patients and a radioiodine scan requires that the patient be rendered hypothyroid for 4-6 wk. In the present study, we analyzed the utility of thallium-201 scanning and the usefulness of magnetic resonance imaging (MRI) in the detection of thyroid cancer. Nineteen patients with thyroid cancer had a total of 24 radioiodine scans, 33 thallium scans, and 10 MRI examinations. Of the 19 patients in the study, 17 had differentiated thyroid carcinoma. In these 17 cases, all paired studies were concordant for the presence (n = 7) or absence (n = 10) of disease. However, in one case (Patient 10), the 201Tl studies showed far more extensive disease than was observed on the 131I scan. Thyroid cancer was also detected on seven MRI studies. In summary, thallium and MRI scans are adjunctive techniques to radioiodine scanning that can either confirm the presence of neck bed activity, residual disease or metastatic cancer and may delineate tumor deposits not detected by radioiodine scanning. Thallium may be capable of detecting tumor deposits even while a patient remains euthyroid.

Mixed myelodysplastic and myeloproliferative syndromes.

Aplastic anemia, myelodysplastic syndromes (MDS) and chronic myeloproliferative diseases (MPD) are stem cell disorders. There is no clear-cut demarcation of them. Hypoplastic MDS displays features of aplastic anemia and MDS, on the other side mixed myelodysplastic and myeloproliferative syndromes (MDS-MPS) develop. In our collection of 566 MDS patients, features of myelodysplasia as well as myeloproliferation, MDS-MPS, were present in 25 patients (4.4%). Twelve patients had at the time of diagnosis megakaryocytic proliferation and thrombocythemia beside signs of MDS, and seven had myelodysplasia with granulocytic proliferation and leukocytosis. In another six patients, MDS was the first diagnosis and the proliferative phase developed later during the course of the disease. These patients can be characterized as MDS-MPS in evolution. All subjects had a variable degree of anemia. While the level of thrombocythemia has been relatively stable, the number of leukocytes has been progressive, but rarely extended beyond 100 x 10(9)/l. Ring-sideroblasts and myelofibrosis were frequent findings. Two more homogeneous MDS-MPS groups emerged in our analysis: sideroblastic anemia with thrombocythemia and a group fulfilling the criteria of Philadelphia chromosome negative and bcr-abl negative "atypical chronic myeloid leukemia (aCML)'. One patient with thrombocythemia and three with leukocytosis (23%) transformed to acute myeloid leukemia (AML). Men prevailed (12/13) in patients with leukocytosis and MDS-MPS in evolution. Of the 46% MDS-MPS patients with chromosomal aberrations, del(20)(q) is of interest.

Three cases of near-tetraploid acute myeloid leukemias originating in pluripotent myeloid progenitors.

We report three cases of acute myeloid leukemia (AML) with a near-tetraploid karyotype in most metaphases while lacking chromosomal abnormalities typical for AML. All patients, 63, 72 and 81 years old, were female. In two cases, AML was diagnosed 5-7 months after a cytopenic period while the third patient had a secondary AML after therapy for a pleural tumor. Leukemic blasts were classified as AML M0, AML M1 and AML without further specification. Two patients died on the 18th and 52nd day after the start of cytotoxic chemotherapy, the third patient refused chemotherapy and died 22 days after the diagnosis. The three patients may represent a distinct AML category with the following features: (1) the near-tetraploid karyotype in most bone marrow metaphases examined at diagnosis of AML; (2) the presence of very large myeloid blasts in the bone marrow and dysplastic changes in erythroid and/or megakaryocytic lineages pointing to the origin of AML in pluripotent myeloid progenitor cells; (3) the expression of the CD34 antigen; (4) the low growth of granulocyte-macrophage colony forming cells in culture; and (5) the presence of a preleukemic phase, a higher age and a poor prognosis.

Near-tetraploid poorly differentiated acute myeloid leukemia M0 diagnosed by short-term cultures with a phorbol ester TPA.

Leukemic blasts of two patients with acute leukemia exhibited similar characteristics. They were heterogeneous in size with a diameter of 14-30 microns in smears and unclassifiable by morphological, cytochemical, immunophenotypic and ultrastructural examinations. Cytogenetic examinations of both revealed a near-tetraploid karyotype. Blasts from both patients differentiated into macrophages in cultures with 10 ng/ml 12-O-tetradecanoylphorbol-13-acetate (TPA) which is a feature specific for myeloid blasts and the cases were thus classified as poorly differentiated acute myeloid leukemias (AML M0). Near-tetraploid poorly differentiated acute myeloid leukemias M0 seem to be a special category of AML in the morphologic, immunologic and cytogenetic (MIC) classification. The presence of very large blasts in the heterogeneous blast population in acute unclassified leukemias could be a morphological sign of near-tetraploid leukemias AML M0.

Partial trisomy of 3q detected by chromosome painting in a case of juvenile chronic myelomonocytic leukemia.

Juvenile chronic myelomonocytic leukemia (JCMMoL) is a rare disease with no specific type of chromosome aberration yet delineated. We report a 2-year-old boy who had in his leukemic bone marrow (BM) and peripheral blood (PB) cells the 46,XY,der(15)t(3;15)(q13.1;q26) karyotype. Phytohemagglutinin (PHA)-stimulated lymphocytes of peripheral blood had a normal 46,XY karyotype. The origin of the duplicated part of 3q was proved by fluorescence in situ hybridization (FISH) with the pHSR(sat III 15p) DNA probe and a chromosome 3-specific DNA library (i.e., chromosome painting). The chromosome finding in our case provides further proof of the close relationship between the rearrangement in region 3q13-->3q26 and the pathogenesis of acute myeloid leukemia (AML). Our patient has transformed into erythroleukemia [M6 according to the French-American-British (FAB) classification] during the course of the disease.

Derivative (6)t(1;6)(q22;p21) revealed in bone marrow cells by FISH 9 months before diagnosis of acute T-lymphoblastic leukemia.

A chromosomal clone with unbalanced translocation resulting in partial trisomy of segment 1q22-qter and partial monosomy of segment 6p21-pter was revealed by fluorescence in situ hybridization (FISH) using a panel of different whole chromosome painting probes. The pathologic clone appeared after sequential chemotherapy treatment for AML-M5 when the patient was in complete remission before development of T-ALL. However, this clone was present during the whole period of treatment for T-ALL. The clone remained the only chromosomal aberration found. Breakpoints were detected more easily and more precisely with the use of the FISH technique than with G-banding only.