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The intestine‐specific caudal‐related homeobox gene‐2 (CDX2) homeobox gene, while being a tumor suppressor in the gut, is ectopically expressed in a large proportion of acute leukemia and is associated with poor prognosis. Here, we report that turning on human CDX2 expression in the hematopoietic lineage of mice induces acute monoblastic leukemia, characterized by the decrease in erythroid and lymphoid cells at the benefit of immature monocytic and granulocytic cells. One of the highly stimulated genes in leukemic bone marrow cells was BMP and activin membrane‐bound inhibitor (Bambi), an inhibitor of transforming growth factor‐β (TGF‐β) signaling. The CDX2 protein was shown to bind to and activate the transcription of the human BAMBI promoter. Moreover, in a leukemic cell line established from CDX2‐expressing mice, reducing the levels of CDX2 or Bambi stimulated the TGF‐β‐dependent expression of Cd11b, a marker of monocyte maturation. Taken together, this work demonstrates the strong oncogenic potential of the homeobox gene CDX2 in the hematopoietic lineage, in contrast with its physiological tumor suppressor activity exerted in the gut. It also reveals, through BAMBI and TGF‐β signaling, the involvement of CDX2 in the perturbation of the interactions between leukemia cells and their microenvironment., Abnormal expression of the homeodomain transcription factor caudal‐related homeobox gene‐2 (CDX2) is associated with poor prognosis of leukemia patients. Here, we report that turning on human CDX2 expression in the hematopoietic lineage of mice induces acute monoblastic leukemia, through inhibition of the lymphocytic lineage and accumulation of immature monoblasts mediated by the stimulation of the BMP and activin membrane‐bound inhibitor that blocked transforming growth factor‐β‐dependent differentiation of monocytes.

Disseminated intravascular coagulation (DIC) is usually observed in acute promielocytic leukemia (AML-M3). DIC is diagnosed in other types of acute myeloid leukemia less frequently, but among them, the largest percentage applies to patients with acute monoblastic leukemia (AML-M5), with the release of procoagulation substances and cytokines from blasts. Laboratory and clinical symptoms of DIC appeared at the time of diagnosis of leukemia or just after initiation of induction treatment. We present two children with AML-M5 and rearrangement of the MLL gene, treated according to BFM AML 98 Interimphase 2004 and BFM AML 2012 protocol. The first patient had laboratory signs of DIC as undetectable (below quantifiable levels of) coagulation parameters without any clinical symptoms diagnosed at the same time as leukemia and persistent during the induction chemotherapy. The second patient had changes first in the coagulogram on the second day of induction chemotherapy. In the subsequent days, major bleeding from mucous membranes of the oral cavity, requiring intensive substitute treatment, was observed. The highest concentration of D-dimers with the lowest concentration of fibrinogen was observed on day 5 of chemotherapy in both the cases. Coagulation parameters were within normal levels on the last day, e.g. on Day 8 of induction chemotherapy, despite intensive substitution therapy.

At present diagnosis of acute leukemia does not represent any difficulties and is based on morphological and immunophenotypical bone marrow studies. The paper presents a non-standard verification algorithm of acute monoblastic leukemia in elderly female patient, with leukemic skin lesion. Morphologic and immunohistochemical studies of biopsy materials of skin, lymph node and bone marrow allow establishing a linear membership of tumor cells and promptly verifying the diagnosis of leukemia. Lack of the overall clinical examination in such cases leads to diagnostic errors and to late verification of the true diagnosis and significantly worsens the prognosis.

Armillaridin (AM) is an aromatic ester compound isolated from Armillaria mellea. Treatment with AM markedly reduced the viability of human chronic myelogenous leukemia K562, chronic erythroleukemia HEL 92.1.7, and acute monoblastic leukemia U937 cells, but not normal human monocytes, in a dose- and time-dependent manner. Treatment of K562 cells with AM caused changes characteristic of autophagy. Only a small amount of AM-treated K562 cells exhibited apoptosis. By contrast, AM treatment resulted in extensive apoptotic features in U937 and HEL 92.1.7 cells without evident autophagy. The autophagy of K562 cells induced by AM involved autophagic flux, including autophagosome induction, the processing of autophagosome-lysosome fusion and downregulation of BCL2/adenovirus E1B 19 kDa interacting protein 3 (BNIP3). By bcr-abl knockdown, the growth inhibition of K562 cells caused by AM was partially blocked, suggesting that AM-induced cell death might be a bcr-abl-dependent mode of autophagy-associated cell death. In conclusion, AM is capable of inhibiting growth and inducing autophagy-associated cell death in K562 cells, but not in normal monocytes. It may have potential to be developed as a novel therapeutic agent against leukemia.

A 70-year-old female was referred for brown-to-gray colored papules and nodules on her lower legs. She had been diagnosed with diffuse large B-cell lymphoma (DLBCL) in her stomach, and myelodysplastic syndrome (MDS) by bone marrow biopsy. Three years after complete remission of DLBCL, she experienced DLBCL recurrence in her small bowel and was hospitalized. MDS had been stationary, but during the treatment of DLBCL, her laboratory findings suggested signs of leukemia. Bone marrow biopsy was done, and acute monoblastic leukemia (AMoL) was diagnosed. After 1 cycle of chemotherapy for AMoL, skin lesions developed, and her skin biopsy showed cutaneous T-cell lymphoma (CTCL). Terminal deoxynucleotidyl transferase staining and CD123 staining were negative, and bone marrow re-biopsy conducted after the skin lesion developed still showed monoblastic proliferation. Whether the CTCL represented with an AMoL lineage switch could not be completely proved due to the absence of molecular or clonal marker evaluations, but the possibility of coexistence of three different malignancies was higher. During treatment, a neutropenic fever developed, and the patient died due to sepsis. We herein report a rare case of CTCL accompanied by AmoL and DLBCL.

Acute monoblastic leukemia (AMoL) is characterized by cells with highly undifferentiated morphology. Cytochemistry with non-specific esterases is negative in up to 20% of cases. Immunophenotyping by flow cytometry has an essential role in diagnosing such a subtype of leukemia and a multiparametric approach with a wide monoclonal antibody panel is necessary. We describe a case of AMoL with morphology resembling either plasma blasts or very immature erythroblasts. Diagnosis was made by alpha-naphtyl-acetate esterase staining and with immunophenotyping, which was made with a wide monoclonal antibody panel. Blasts were positive for monocytic markers. Most of leukemic cells, however, were positive for Glycophorin-A. The presence of Glycophorin-A, which is considered as a specific marker of the erythroid lineage, has never been reported previously in cases of AMoL. This peculiar immunophenotype might be interpreted as deriving from a common myelo-erythroid precursor undergone leukemic transformation.

[Figure][1] A 31-year-old white man presented with a 6-week history of symptoms of anemia, progressive hearing loss, and periorbital edema. Clinical examination revealed striking periorbital swelling (panels A-B) and periauricular edema with resultant tympanic membrane obstruction. No

Introduction: Isolated leukemic infiltration of peripheral nerves without central nervous system involvement, or isolated neuroleukemiosis, is an extremely rare complication of leukemia. Methods: We report the case of a patient with isolated neuroleukemiosis and review the pertinent literature. Results: A man with a 12-year history of acute monoblastic leukemia presented with median mononeuropathy. Magnetic resonance imaging revealed a thickened median nerve. Nerve biopsy confirmed the diagnosis of leukemic infiltration. Clinical resolution was achieved through local radiation. Only 10 cases of isolated neuroleukemiosis have been reported. Most were in remission from leukemia. Our patient is the only one who was considered clinically cured of leukemia. Conclusions: The presumed pathophysiology of isolated neuroleukemiosis is hematogenous spread of leukemic cells into the peripheral nervous system across the blood–nerve barrier. It should be considered in the differential diagnosis in patients with leukemia who present with neuropathy, even when they are considered to be clinically cured of leukemia. Muscle Nerve 51: 290–293, 2015

Acute myeloid leukemia (AML) is a malignant hematopoietic stem cell disorder which is sub-classified based on bone marrow morphology and the presence of specific genetic abnormalities. One such cytogenetic abnormality is the pericentric inversion (inv) of chromosome 16 which is typically seen in AML M4 with eosinophilia and is associated with a favorable prognosis. We report the inv (16) in a young woman with AML M5 and abnormal eosinophils. This is a rare entity with only about 20 cases being reported till date.

Background/Aims: It has been demonstrated that KRAS mutations represent about 90% of cancer-associated mutations, and that KRAS mutations play an essential role in neoplastic transformation. Cancer-associated RAS mutations occur frequently in acute myeloid leukemia (AML), suggesting a functional role for Ras in leukemogenesis. Methods: We successfully established a mouse model of human leukemia by transplanting bone marrow cells co-transfected with the K-ras (G12D) mutation and AML1/ETO fusion protein. Results: Mice transplanted with AML/ETO+KRAS co-transduced cells had the highest mortality rate than mice transplanted with AML/ETO- or KRAS-transduced cells (115d vs. 150d). Upon reaching a terminal disease stage, EGFP-positive cells dominated their spleen, lymph nodes, peripheral blood and central nervous system tissue. Immunophenotyping, cytologic analyses revealed that AML/ETO+KRAS leukemias predominantly contained immature myeloid precursors (EGFP+/c-Kit+/Mac-1-/Gr-1-). Histologic analyses revealed that massive leukemic infiltrations were closely packed in dense sheets that effaced the normal architecture of spleen and thymus in mice transplanted with AML1/ETO + KRAS co-transduced cells. K-ras mRNA and protein expression were upregulated in bone marrow cells of the K-ras group and AML1/ETO + Kras group. The phosphorylation of MEK/ERK was significantly enhanced in the AML1/ETO + Kras group. The similar results of the AML1/ETO + Nras group were consistent with those reported previously. Conclusion: Co-transduction of KrasG12D and AML1/ETO induces acute monoblastic leukemia. Since expression of mutant K-ras alone was insufficient to induce leukemia, this model may be useful for investigating the multi-step leukemogenesis model of human leukemia.

Secondary leukemias are usually forms of leukemias which are developed due to therapy administered for a previous malignancy. Radiotherapy or chemotherapy induced leukemia is a complication which follows treatment of a different primary malignancy. A case of acute monoblastic leukemia following treatment of the invasive carcinoma cervix (treated by radiotherapy and chemotherapy) is reported. This secondary leukemia developed one year after treatment. This case is being presented due to its rarity.

Survival of acute myeloid leukemia (AML) cells is regulated by their adherence to bone marrow stromal environment. Several adhesion molecules mediate interactions between AML cells and stroma, but their specific role in AML cell survival is still poorly understood. Here, we show that CD44 activation with the Hermes-3 monoclonal antibody enhances primary AML5 blast survival and increases apoptosis resistance of THP-1 monoblastic leukemia cells. Moreover, we show that CD44 activation upregulates the anti-apoptotic Mcl-1 protein and that Mcl-1 is essential for apoptosis resistance of THP-1 cells. These results suggest that Mcl-1 inhibitors might be required to block pro-survival activity of CD44 in AML5.

This report describes a patient with extramedullary relapse of acute myeloid leukemia (AML) without involving bone marrow. A 57-year-old man was diagnosed as having acute monoblastic leukemia with t(9;11)(p22;q23) and trisomy 8. Ten months after achieving complete response (CR) with chemotherapy, masses developed in his left forearm and in the back of his thigh, preceded by enigmatic peripheral neurological symptoms. Aspiration from the forearm showed leukemic relapse, and fluorescence in situ hybridization (FISH) revealed that the majority of the cells had 11q23 anomaly and tetrasomy 8. Bone marrow or meningeal relapse was not observed. To our knowledge, this is the first case report of clonal evolution associated with the development of myeloid sarcoma as a relapse in AML.

Rearrangements of the mixed-lineage leukemia (MLL) gene have been associated with a poor prognosis in infant acute lymphoblastic leukemia (ALL). Previously, MLL translocations involving the CREP-binding protein (CREBBP) gene at chromosome band 16p13.3 have primarily been reported in treatment-related acute myeloid leukemia, after chemotherapy for other primary malignancies using topoisomerase II inhibitors. We report a case of de novo infant ALL with t(11;16)(q23;p13.3). After chemotherapy, this patient developed an acute monoblastic leukemia (M5b) with retention of the t(11;16)(q23;p13.3), indicating that this is a lineage switch of the original leukemic clone. To our knowledge, these findings have not been previously reported.

We describe a patient with acute promyelocytic leukemia (APL) and the karyotype 46,XX,i(17)(q10) with PML-RARA fusion gene detected by fluorescence in situ hybridization (FISH) and nested reverse transcriptase-polymerase chain reaction (RT-PCR). FISH using dual-color translocation probes for PML (promyelocytic leukemia) and RARA (retinoic acid receptor-alpha) showed fusion signal for PML-RARA on both arms of i(17q). The patient attained complete remission (CR) with all-trans retinoic acid treatment and became PML-RARA negative. One year later, while PML-RARA negative on FISH and RT-PCR, the patient presented with thrombocytopenia. Bone marrow examination suggested an acute monoblastic leukemia (AML-M5a) including the karyotype 46,XX,t(8;16) (p11.2;p13.3),inv(11)(p15q22 approximately q23)[11]/47,idem,+i(8)(q10)[9]. She is currently in CR. The occurrence of therapy related acute leukemia after successful therapy for APL is an emerging problem.

Spontaneous remission in patients with acute myeloid leukemia (AML) is a rarely reported phenomenon of usually short duration. The etiology remains unclear, but an association with preceding blood transfusions or bacterial infections has been reported. Triggered immune responses are suggested to play a potential role in the development of spontaneous remission. Acute monocytic leukemia was diagnosed in a 61-yr-old male patient. Cytogenetic analysis revealed a sole translocation (9;11) (q22;q23) and RT-PCR the MLL/AF9 fusion gene. As a result of the patient's reduced performance status and septic condition, cytostatic therapy was withheld. No microorganisms could be detected. Hematologic and molecular remission occurred after initiating antibiotic therapy without any cytostatic treatment; 29 months after the initial diagnosis, he is in complete remission, and excellent physical condition. Our report includes a review of the literature since 1985, reporting cases of patients with AML and spontaneous remission together with informative cytogenetics. Balanced translocations such as in core binding factor (CBF) leukemias appear somewhat overrepresented. We speculate that AML-specific T cells might be relevant for induction of spontaneous remission and need to be further investigated.

Myelodysplastic syndromes (MDS) are associated with cell maturation defects that can manifest as abnormal surface antigen expression. We describe a patient with refractory anemia with excess blasts, who presented with infection and extensive dysplastic features in peripheral blood granulocytes. The granulocytes expressed CD11b, CD13, CD15, CD33, and CD43. The granulocytes also expressed CD4 antigen. Cytogenetic analysis showed a clonal t(5;12)(q33;p13). The patient improved on antibiotics with partial improvement in the dysplastic features. However, shortly after, the patient experienced paravertebral extramedullary blast transformation followed by a leukemia phase of acute monoblastic leukemia. The patient died a few days later. This is the first report describing anomalous expression of CD4 on granulocytes in MDS. Since the breakpoint on chromosome 12 is near the CD4 gene, which is mapped to 12p12, we hypothesize that dysregulation of the CD4 gene may have occurred resulting in its persistent expression on mature and maturing granulocytes.

Hepatic venoocclusive disease (VOD) is the most common complication of cytoreductive therapy used for stem cell transplantation, but it is rarely encountered during induction treatment of acute leukemia. We describe a patient in whom severe clinical VOD developed shortly after induction treatment for acute monoblastic leukemia. Administration of intravenous defibrotide for 19 days induced complete resolution of the VOD. Further consolidation treatment was resumed including high-dose cytosine arabinoside without further complications.

Lymphohematopoietic malignancies are common spontaneous diseases of dogs whose clinical presentation and biologic behavior closely resemble their human counterparts. The goal of this study was to define the potential to use canine lymphoma and leukemia as suitable models to refine therapeutic approaches targeting the interleukin-2 receptor (IL-2R). The authors evaluated the patterns of IL-2R expression in 13 dogs with multicentric non-Hodgkin's lymphoma (NHL) and in six dogs with leukemia (acute lymphocytic leukemia, n = 3; chronic lymphocytic leukemia in blast crisis, n = 1; acute monoblastic leukemia, n = 2). The authors first cloned and sequenced the complete coding domains of the wild-type canine IL-2R alpha-chain gene. They next used qualitative reverse transcription polymerase chain reaction (RT-PCR) analysis to examine IL-2R alpha, beta, and gamma(c) subunit expression in the tumors. Messenger RNA (mRNA) for the interleukin-2 receptor alpha, beta, and gammac subunits that comprise the high-affinity receptor was present in samples from all dogs with NHL. Expression of functional surface IL-2R also was observed flow cytometrically in NHL cells from all four dogs tested. Leukemic cells from one dog with B cell acute lymphocytic leukemia and two dogs with acute monoblastic leukemia expressed mRNA for all three subunits, whereas cells from another dog with B cell leukemia and both dogs with T cell leukemia expressed only mRNA for the beta and gammac subunits that comprise the intermediate-affinity receptor. These results indicate that the IL-2R is commonly expressed in canine lymphohematopoietic malignancies, and support the suitability of this large-animal model to evaluate targeted IL-2R cancer therapy using approaches of interest in the treatment of humans with hemolymphatic cancers.

RATIONALE Central nervous system (CNS) leukemia is a frequent diagnosis in pediatric acute myeloblastic leukemia (AML) and includes neural symptoms. However, CNS leukemia is rarely associated with central hypsothyroidism. PATIENT CONCERNS AND DIAGNOSES A 2-year-old female with AML with MLL rearrangement presented with CNS infiltration. Laboratory tests suggested the presence of central hypothyroidism (thyroid-stimulating hormone [TSH]: 0.48 mIU/ml, normal range 0.7-6.4 mIU/ml; serum free thyroxine [FT4]: 0.62 ng/dl, normal range 0.8-2.2 ng/dl; free triiodothyronine: 1.57 pg/ml, normal range 2.7-5.6 pg/ml). Magnetic resonance imaging detected no lesions in the hypothalamus, pituitary, or thyroid. INTERVENTIONS AND OUTCOMES Levothyroxine (2.5 mg/kg/day) was administered together with chemotherapy and intrathecal injection of methotrexate, cytarabine, and hydrocortisone into the cerebrospinal fluid. The FT4 concentration increased after levothyroxine treatment, but later decreased after relapse of CNS leukemia. The TSH concentrations remained low. After remission of CNS leukemia, the TSH and FT4 concentrations quickly recovered to their normal ranges. LESSONS We believe that the CNS leukemia directly affected TSH and thyroid hormone secretion in our patient.

The v-myb(AMV) oncogene transforms myelomonocytic cells in vitro and induces acute monoblastic leukemia in chickens. We analyzed the activity of the evolutionarily conserved PEST-like domain (P1 domain) for biochemical and biological activities of v-Myb in ex vivo cultures and in vivo. Deletion of the P1 domain did not affect v-Myb transcriptional activity, intracellular stability, or subcellular localization. However, it resulted in subtle yet important changes in biological activities. Although the mutant DeltaP1 v-Myb protein blocked the terminal differentiation of the monocyte/macrophage lineage as efficiently as the wild type (wt) in ex vivo cultures, it failed to induce the acute phase of monoblastic leukemia, with its fatal consequences, in vivo. Interestingly, in DeltaP1 v-myb-infected animals large numbers of monoblasts, comparable to those induced by wt v-myb, were present in the bone marrow but very few were found in the peripheral blood. The comparison of ex vivo wt- and DeltaP v-Myb bone marrow cells revealed several important features of v-Myb transformation: (i) the proliferation of transformed monoblasts is not an apparent consequence of the differentiation block with these processes being at least in part independent; (ii) the P1 domain is required for proliferation of v-Myb-mediated transformed monoblasts; (iii) the mechanism which renders transformed cells growth factor independent does not involve activation of an autocrine growth factor loop; and (iv) deletion of the P1 domain affects self-adhesion properties of v-myb-transformed monoblasts as well as their interaction with bone marrow stromal cells. These data indicate that the DeltaP1 v-myb mutant and ex vivo bone marrow cell cultures represent a valuable tool for studies on the mechanisms of leukemia formation.

We report a case of acute monoblastic leukemia with t(8;16) in a 71-year-old man who had rapid rise of leukocyte counts from 20.3 × 109/l to 62.7 × 109/l in two weeks. The peripheral blood showed many granular promonocytes that led to the consideration of acute promyelocytic leukemia of the hypogranular variant. The bone marrow, however, revealed mainly monoblasts with erythrophagocytosis. Cytogenetic study finally confirmed the diagnosis of acute monoblastic leukemia with t(8;16). The patient died three days after admission. The demonstration of these two characteristic features of this subtype, granular promonocytes and erythrophagocytosis by monoblasts, separately, in the peripheral blood and bone marrow is unusual and misleading. This cytogenetic abnormality can be demonstrated only in M5 and M4 with characteristic clinical features of disseminated intravascular coagulation, extramedullary involvement, and poor prognosis. Although it is not a common disease, this specific subtype of acute myelogenous leukemia is consistently associated with a specific cytogenetic marker, thus it should be considered a distinct clinicopathologic entity. Am. J. Hematol. 66:207–212, 2001. Published 2001 Wiley-Liss, Inc.

We report two cases of atypical defibrination syndromes in patients with respectively acute monoblastic leukemia (chronic myeloid leukemia initially) and acute lymphoblastic leukemia. Hemostasis studies show low fibrinogen level, elevated D-dimers, decreased alpha 2 antiplasmin and factor V, normal antithrombin III values. Plasminogen is below the normal range in one patient. Soluble complexes, which are an important argument for diagnosis of intravascular coagulation disease, are not detected in both patients. Primary or secondary hyperfibrinolysis seems also excluded since euglobulin clot lysis time was normal. Enzymatic proteolysis of fibrinogen (or fibrin) by the blast cells has been reported by some authors; this mechanism could account for the hemostasis abnormalities observed in these two patients.

The accurate genetic classification of acute leukemia is of the utmost clinical importance for treatment stratification. In the present study, we report on a young girl with aggressive acute monoblastic leukemia (AML) (M5b) with skin, lymph node, and bone marrow involvement, in whom cytogenetic analysis revealed three clones with different secondary chromosomal changes. Two clones had the secondary +8 and del(9q) aberrations, with the der(11)t(1;11) in the second one; the third clone was apparently unrelated to the others, and had add(7)(p?21),-13,+22. Using the spectral karyotyping (SKY) technique, we found that all three clones originated from a common clone that harbored the hidden primary t(10;11)(p13;q23) or its derivatives, suggesting clonal evolution. The first clone had the balanced t(10;11), the second had its derivative, der(10)t(10;11), and the third had the other derivative, der(11)t(10;11). On fluorescence in situ hybridization (FISH), MLL gene splitting, with translocation of its centromeric portion to 10p, and deletion of its telomeric portion, was demonstrated. In conclusion, the detection of the very poor prognostic t(10;11) aberration in AML, was possible by complementing the traditional cytogenetic analysis with SKY and FISH.

A patient with acute monoblastic leukemia (AML M5a) and the pericentric inversion inv(8)(p11q13) as well as additional chromosome abnormalities in her bone marrow cells is described. This is the fourth known case of inv(8)(p11q13)-positive acute leukemia, and the second such case in which gain of 1q material occurred during clonal evolution. All patients with acute leukemia and inv(8)(p11q13) have been females, most have been young, and there has been a tendency for the disease to run an aggressive course. Both hematologically and cytogenetically, therefore, inv(8)(p11q13)-positive leukemia may be viewed as a variant of AML with t(8;16)(p11;p13). This similarity is also apparent at the molecular genetic level, in-as-much as the MOZ gene in 8p11 is rearranged in both the translocation and the inversion; in t(8;16)-positive leukemia, a MOZ-CBP chimeric gene is generated, whereas inv(8) has been shown to generate a MOZ-TIF2 fusion gene. Southern blot analysis of the present case after MOZ0.8 hybridization of Bam HI digested DNA gave an 11 kb aberrant band in addition to the germline band, corresponding to a breakpoint immediately upstream of the 4 kb long MOZ exon that begins at position 3746. Also previously investigated inv(8)-positive leukemias have shown breaks in this intron indicating that it contains sequence motifs predisposing to illegitimate recombination.

The authors present a case of monocytic aleukemic leukemia cutis in which skin symptoms were the sole manifestation of the leukemia during the first year and a half of the disease. Diagnostic difficulties, the importance of immunhistochemical markers, and the prognosis and therapy of aleukemic leukemia cutis are discussed.

A 1.6-year-old male domestic short hair cat was brought to the Veterinary Medical Teaching Hospital, Kasetsart University, with signs of severe anemia, depression, and general lymph node enlargement. Complete blood count revealed leukocytosis and massive undifferentiated blasts. Testing for antibodies specific to feline leukemia virus (FeLV) was positive, and FeLV nucleic acid was confirmed by nested polymerase chain reaction. Base on cytochemistry and ultrastructure, the cat was diagnosed with acute monoblastic leukemia.

OBJECTIVE: To study the role of testicular fine needle aspiration (FNA) in the diagnosis of leukemia relapse. STUDY DESIGN: The study group consisted of 32 leukemia patients in complete remission for one to five years. Their ages ranged from 8 to 63 years. Twenty-five of them had bilateral testicular enlargement, and seven had unilateral enlargement. Hematologic workup and bone marrow studies of all of the patients showed no evidence of leukemia (full remission). FNA smears were obtained by using 22-gauge needles fitted to 20-mL syringes. RESULTS: The smears revealed 13 cases of acute lymphoblastic leukemia L2 (ALL-L2), 8 of ALL-L3, 5 of acute monoblastic leukemia M5 (AML-M5), 1 of acute promyelocytic leukemia (APL-M3), 1 of AML-M1; 1 of erythroleukemia, AML-M6, 1 of chronic lymphocytic leukemia, 1 of chronic myelogenous leukemia and 1 of plasma cell leukemia. CONCLUSION: FNA study of the testis is safe, time saving, rapid and easy to perform for the diagnosis of testicular leukemia relapse, obviating the need for biopsy.

Cytochemical staining for leukemia typing is declining in hematology laboratories, but the use of flow cytometry may not be possible in some settings. Aberrant cytochemical nonspecific esterase/α-naphthyl acetate esterase (NSE/αNAE) positive B-lymphoblasts can cause confusion with monoblasts, a potentially dangerous pitfall. This unusual cytochemical NSE/αNAE positivity had been associated with relatively poorer outcome of acute lymphoblastic leukemia (ALL) in the era prior to the advent of routine multicolor flow cytometric immunophenotyping. We reviewed morphological, cytochemical and flow-cytometric data from five cases of B-lineage ALL that showed NSE/αNAE positivity and were diagnosed definitively using multi-parametric flow cytometric immunophenotypic analysis. Diffuse or dot-like (localized) strong cytochemical NSE/αNAE activity was detected in all cases and all showed one or more features of high risk disease. The number of NSE/αNAE positive blasts in the marrow varied from 10 to 75%. The morphological differential diagnoses included T-lymphoid lineage ALL and acute monoblastic leukemia (AML-M5). Flow cytometric data revealed B-lineage antigens and the absence of monocytic or other myeloid markers resolved the diagnosis. These cases underscore the importance of immunophenotyping in all cases of suspected ALL regardless of the cytochemical findings. Although the numbers are small, the association with high risk disease observed in all five of our cases may corroborate the previously reported poor prognostic value of such aberrant cytochemical staining.

Purpose : We report a 5-year-old boy with stage 4 neuroblastoma initially diagnosed as having acute monoblastic leukemia (FAB M5A, AMoL), based on bone marrow morphology, histochemistry, immunocytochemistry, immunophenotyping, and cytogenetics, all consistent with AMoL. The patient also had circulating blasts at diagnosis. After failing initial therapy for AMoL and because of concerns about residual blasts with a clumped appearance in the bone marrow, urinary homovanillic acid (HVA) and vanillylmandelic acid (VMA) and N-myc amplification in tumor cells were evaluated and found to be positive, resulting in the diagnosis of neuroblastoma. Abdominal computerized tomography showed a left adrenal mass. A review of 10 reported cases of neuroblastoma with leukemic features showed that seven of them were misdiagnosed as having leukemia, and in six of the seven, the diagnosis of neuroblastoma was made postmortem. Conclusion : Neuroblastoma may be confused with acute leukemia, even with the use of modern techniques.

Intensification of antileukemic treatment and progress in supportive management have improved the survival rates of children with acute myeloid leukemia (AML). However, morbidity and early mortality in these patients are still very high, especially in children with acute monoblastic leukemia (AML FAB M5). Inflammatory syndromes complicating the management of these children after application of cytosine arabinoside and due to hyperleukocytosis at initial presentation have been reported. Hemophagocytic lymphohistiocytosis (HLH) has been described as a serious and life-threatening acute complication during treatment of different oncologic entities; however, data on HLH in children with AML FAB M5 are extremely rare. A retrospective study of all children with AML FAB M5 treated at our institution between 1993 and 2013 was performed to describe the clinical characteristics of patients who developed an inflammatory syndrome with HLH during oncologic treatment. Three of 10 children developed an inflammatory syndrome with fever, elevation of C-reactive protein, hyperferritinemia, elevation of soluble interleukin-2, and hemophagocytosis during prolonged aplasia following the first cycle of chemotherapy not responding to broad-spectrum antibiotics. No infectious agents could be identified; the initial symptoms occurred 17, 18, and 28 days after diagnosis of AML, respectively. The children immediately responded to dexamethasone; however, the same syndrome was observed again after the second cycle of chemotherapy and, in one patient, also after the third cycle. Treating physicians should be aware of an inflammatory syndrome resembling HLH in children with monoblastic leukemia since this problem might extremely complicate management and supportive care of these children. The co-incidence of monoblastic leukemia with HLH might be explained by cytokines released from the monoblastic leukemic cells themselves.

In pediatric acute myeloid leukemia (AML), cytogenetic abnormalities are strong indicators of prognosis. Some recurrent cytogenetic abnormalities, such as t(8;16)(p11;p13),are so rare that collaborative studies are required to define their prognostic impact. We collected the clinical characteristics, morphology, and immunophenotypes of 62 pediatric AML patients with t(8; 16)(p11; p13) from 18 countries participating in the International Berlin-Frankfurt-Munster (I-BFM) AML study group. We used the AML-BFM cohort diagnosed from 1995-2005 (n = 543) as a reference cohort. Median age of the pediatric t(8; 16)(p11; p13) AML patients was significantly lower (1.2 years). The majority (97%) had M4-M5 French-American-British type, significantly different from the reference cohort. Erythrophagocytosis (70%), leukemia cutis (58%), and disseminated intravascular coagulation (39%) occurred frequently. Strikingly, spontaneous remissions occurred in 7 neonates with t(8; 16)(p11; p13), of whom 3 remain in continuous remission. The 5-year overall survival of patients diagnosed after 1993 was 59%, similar to the reference cohort (P = .14). Gene expression profiles of t(8; 16) (p11; p13) pediatric AML cases clustered close to, but distinct from, MLL-rearranged AML. Highly expressed genes included HOXA11, HOXA10, RET, PERP, and GGA2. In conclusion, pediatric t(8; 16)(p11; p13) AML is a rare entity defined by a unique gene expression signature and distinct clinical features in whom spontaneous remissions occur in a subset of neonatal cases.

[Figure][1] A 27-year-old woman presented with multiple red to violaceous dermal nodules on the scalp, abdomen, and external genitalia, and masses in the left breast. A skin biopsy specimen obtained from her left abdomen was suggestive of myeloid sarcoma. A complete blood count showed 40%

Mixed-lineage-leukemia (MLL) fusion oncogenes are intimately involved in acute leukemia and secondary therapy-related acute leukemia. To understand MLL-rearranged leukemia, several murine models for this disease have been established. However, the mouse leukemia derived from mouse hematopoietic stem cells (HSCs) may not be fully comparable with human leukemia. Here we developed a humanized mouse model for human leukemia by transplanting human cord blood-derived HSCs transduced with an MLL-AF10 oncogene into a supra-immunodeficient mouse strain, NOD/Shi-scid, IL-2Rγ(-/-) (NOG) mice. Injection of the MLL-AF10-transduced HSCs into the liver of NOG mice enhanced multilineage hematopoiesis, but did not induce leukemia. Because active mutations in ras genes are often found in MLL-related leukemia, we next transduced the gene for a constitutively active form of K-ras along with the MLL-AF10 oncogene. Eight weeks after transplantation, all the recipient mice had developed acute monoblastic leukemia (the M5 phenotype in French-American-British classification). We thus successfully established a human MLL-rearranged leukemia that was derived in vivo from human HSCs. In addition, since the enforced expression of the mutant K-ras alone was insufficient to induce leukemia, the present model may also be a useful experimental platform for the multi-step leukemogenesis model of human leukemia.

Patients with acute myelogenous leukemia complicate with disseminated intravascular coagulation (DIC), not only at the time of the initially leukemia diagnosis, but also during induction chemotherapy. In Japan, recently, a recombinant human soluble thrombomodulin alpha (Recomodulin) has been introduced as a new type of anti-DIC agent for clinical use in patients with hematological cancer or infectious disease. We describe a 67-year-old female case in which 25,600 units of Recomodulin for 6 days were successfully administered for both initially complicating and therapy-induced DIC without any troubles of bleeding in an acute monoblastic leukemia (AML-M5a) patient with theMLL genetranslocation. Furthermore, the levels of DIC biomarkers recovered rapidly after the Recomodulin treatment. Our case suggests that DIC control using Recomodulin is one of the crucial support-therapies during remission induction chemotherapy in patients with acute leukemia of which type tends to complicate extramedullary or extranodal infiltration having potential to onset DIC.

Acute monoblastic leukemia (acute myeloid leukemia [AML], French-American-British type M5a) with leukemia cutis developed in a patient 6 weeks after the initiation of erythropoietin (EPO) therapy for refractory anemia with ringed sideroblasts. AML disappeared from both marrow and skin after the discontinuation of EPO. Multiparameter flow cytometric analysis of bone marrow cells demonstrated coexpression of the EPO receptor with CD45 and CD13 on the surface of blasts. The incubation of marrow cells with EPO, compared to without, resulted in 1.3- and 1.6-fold increases, respectively, in tritiated thymidine incorporation and bromodeoxyuridine incorporation into CD13+ cells. Clinical and laboratory findings were consistent with the EPO-dependent transformation of myelodysplastic syndrome (MDS) to AML. It is concluded that leukemic transformation in patients with MDS treated with EPO may be EPO-dependent and that management should consist of the discontinuation of EPO followed by observation, if clinically feasible.

A case of leukemia cutis (LC) of monocytic lineage in a patient with myelodysplastic syndrome (MDS) is presented. Cutaneous infiltrates were recognized concurrent with diagnosis of refractory anemia (RA) with monocytosis. Skin infiltrates subsequently spontaneously regressed although MDS progressed with increasing monocytosis, anemia, and thrombocytopenia. Death occurred 6 months after diagnosis with evolution of acute monoblastic leukemia complicated by sepsis. This case supports previous observations of poor prognosis associated with leukemia cutis. LC associated with MDS is reviewed including the role of monocytes.

A 64 year-old Japanese man who developed acute monoblastic leukemia during the course of adult T-cell leukemia/lymphoma (ATL) was studied. Leukemic cells in the peripheral blood and bone marrow were monoblasts positive for alpha-naphthol butyrate esterase (alpha-NBE) staining, CD11c and CD36 antigens, whereas tumor cells in the pleural effusion were ATL cells positive for CD2, CD4, CD25, CD29 and CD45RA antigens. These two malignant cells had different chromosomal abnormalities. Monoclonal integration of human T-cell leukemia virus type I (HTLV-I) proviral DNA and T-cell receptor C beta gene (TCR C beta) rearrangement were detected in the ATL cells, but not in the leukemic monoblasts. By polymerase chain reaction (PCR) in the peripheral blood mononuclear cells (CD11c+ 98%, CD2+ 4%, CD20+ 0%) not containing ATL cells, the presence of the gag region of HTLV-I was confirmed. These facts indicate that a double positive T cell (CD29+, CD45RA+) was possibly the target cell for HTLV-I infection and that HTLV-I was not directly related to the oncogenesis of the monocyte lineage in the present case, even if it did infect the monocytes. However, there is still an outside possibility that HTLV-I induced acute monoblastic leukemia indirectly.

We report a case of acute monoblastic leukemia showing a jumping translocation with the MLL gene in a 17-year-old male. Classic cytogenetic and spectral karyotyping revealed a complex karyotype, and fluorescence in situ hybridization (FISH) demonstrated amplification of the MLL gene followed by translocation to chromosomes 15q, 17q, and 19q. In addition, molecular analyses showed a high expression of AURKA and AURKB genes. It is already known that overexpression of Aurora kinases is associated with chromosomal instability and poor prognosis. The formation of jumping translocations is a rare cytogenetic event and there is evidence pointing toward preferential involvement of the heterochromatin region of donor chromosomes and the telomere ends of recipient chromosomes. Jumping translocation with the MLL gene rearrangement is an uncommon phenomenon reported in leukemia cytogenetics.

The recurring chromosomal 9;II translocation [t(9; II) (p22;q23)] typically is associated with acute monoblastic leukemia, but a number of patients with acute lymphoblastic leukemia also have been reported to have the t(9; II). To investigate the cell lineage in the latter cases, we analyzed DNA from the leukemic cells of an 8-year-old girl with acute lymphoblastic leukemia and a t(9;I I) for rearrangements of the immunoglobulin and T-cell receptor genes. Rearrangements of both immunoglobulin heavy-chain loci and of one lambda light-chain gene were detected, as well as deletions affecting both alleles of the kappa light-chain genes; T-cell receptor genes were in germline configuration. These results provide further evidence that the 9; I I translocation is not limited to myeloid lineage leukemia and may be observed in acute lymphoblastic leukemia.

We describe the clinical course of a 61 years old patient who developed fulminant acute monoblastic leukemia (MSA, FAB) while still on systemic chemotherapy for an advanced adenocarcinoma of the ovary. The leukemia developed following chemotherapy with Cyclophosphamide and Cisplatin (9 cycles), and then Cyclophosphamide and Carboplatin (6 cycles) resulting in a partial remission of the ovarian tumor. Survival from the onset of acute leukemia was extremely short and the cause of death was intracerebral bleeding. Cytogenetic analysis of the leukemic cells revealed a 9:11 translocation, a pattern usually occurring in de novo leukemias. The literature on the association of solid tumors, particularly ovarian cancer, with acute leukemia is reviewed; while systemic chemotherapy for ovarian cancer definitely increases the risk of secondary leukemia, especially if alkylating agents are administered, the occurrence of leukemia during the administration of chemotherapy for the solid tumor is distinctly unusual. Our patient seems to be an additional example of a recently described therapy-related variant of acute leukemia developing shortly after the onset of chemotherapy and characterized by a rapidly downhill clinical course, a monocytic lineage and a cytogenetic rearrangement t(9;11)(p22;q23). While the number of these newly described cases is still small, this additional example should increase the awareness of this potential association in Cisplatin-treated patients.

Dear Editor, Translocations involving chromosomal band 11q23 are found in most of the infant acute lymphoblastic leukemia and in acute myeloblastic leukemia. The majority of these translocations lead to the rearrangement of the MLL gene and the formation of new chimeric genes [1]. We report here a case of congenital acute monoblastic leukemia and myeloid sarcoma associated with an apparent t(1;11)(p36; q23) which proved to be in fact a complex 1;19;11 translocation. This female child was born after a pregnancy of 33 weeks and 6 days complicated by gravidic toxemia and hydramnios. At birth, the baby was cyanosed and showed no reaction to stimuli. She had disseminated intravascular coagulation with petechiae and hematoma on the neck and the limbs. Cutaneous tumors were observed on the abdomen, the right arm and the left thigh. Her hematological data were as follows: hemoglobin 14 g/dl, white blood cells (WBC) 162×10/L with 0.5% neutrophils, 0.5% eosinophils, 9.5% lymphocytes, 8% monocytes and 80% monoblasts and promonocytes, and platelets 50×10/L. A diagnosis of acute monoblastic leukemia (FAB type M5) was made. The biopsy of one cutaneous tumor showed a massive derma infiltration by monoblasts; therefore, these skin tumors were considered to be myeloid sarcomas. Palliative care solely was applied. The child developed acute renal insufficiency and massive cerebral hemorrhage, of which she died 24 h after birth [2]. Cytogenetic analysis was performed on bone marrow cells with standard techniques. We observed a translocation which appeared to be balanced in R-banding between chromosomes 1 and 11; thus, the karyotype was written as 46,XX,t(1;11)(p36.2;q23). FISH analysis using the LSI MLL dual color probe (Abbott, Rungis, France) confirmed the disruption of the MLL gene. It showed the translocation of the 3′ region of MLL (red signal) to the derivative chromosome 1 while the 5′ region (green signal) remained on the der(11). We then used long-distance inverse PCR (LDI-PCR) to identify the MLL fusion partner involved in the chromosomal translocation of that particular patient [3]. Genomic DNA was isolated from methanol/acetic acid-fixed cells of leukemia patient that were stored at −20°C. DNA was extracted using the QIAamp DNA mini kit (Qiagen GmbH, Hilden, Germany) according to the manufacturer recommendations. After DNA digestion, resulting DNA fragments were re-ligated to form DNA circles prior to LDIPCR studies. LDI-PCR reactions were performed as Ann Hematol (2009) 88:795–797 DOI 10.1007/s00277-008-0656-8

Trisomy 8 is one of the most frequent numerical chromosomal abnormalities observed in hematological malignancies, whereas tetrasomy 8 is a clonal aberration seen mainly in myeloid disorders such as acute myelod leukemia (AML) and myelodysplastic syndromes. In contrast to trisomy 8, tetrasomy 8 is a rare chromosomal aberration, in that only 17 reported AML cases with isolated tetrasomy 8 have been documented. Interestingly, the majority of reported cases were associated with monocytic-lineage leukemias. According to recent reports, tetrasomy 8 is regarded as a poor prognostic factor, and most patients having this abnormality relapsed and died within 1 yr. Here, we report a patient with acute monoblastic leukemia having tetrasomy 8 and a very aggressive disease course.