Acute Lymphoblastic Leukemia Transformation with a Precursor B-Cell Immunophenotype to Burkitt's Lymphoma: a Case Report.

Background: As a new point, some very rare features can be revealed as initial diagnosis of acute lymphoblastic leukemia (ALL) without any evidence of lymphoma-like behavior which after initial recovery, presents with new evidence of lymphoma. Herein, a case of the immunophenotypes of blast cells in B-cell precursor acute lymphoblastic leukemia originated from MYC gene-related that was evidenced later by burkitt lymphoma feature. Case Presentation: Our case was initially diagnosed as a typical B-cell ALL cells with L1 morphology in peripheral blood smear and bone marrow aspiration that was not recovered and referred again that was finally featured as burkitt's lymphoma with L3 morphological feature. Conclusion: Thus, in the primary diagnosis of B-cell ALL and especially in cases with treatment failure, the final feature of burkitt's lymphoma should be potentially in mind.

Use of the osmolal gap in diagnosing mixed physiology hyponatremia in a child with B-cell acute lymphoblastic leukemia.

Hyponatremia is common among children undergoing treatment for hematologic malignancies and may be attributed to multiple underlying causes. In cases of hyponatremia due to mixed physiology, the osmolal gap, can identify pseudohyponatremia that may be masked by other causes.

The incidence, risk factors, and outcomes of symptomatic avascular necrosis of bone among Chinese pediatric patients with acute lymphoblastic leukemia.

BACKGROUND: Avascular necrosis (AVN) of bone is a debilitating complication of pediatric patients with acute lymphoblastic leukemia (ALL). While it is extensively studied and reported in Western population, studies focused on Orientals are limited. This study aims to evaluate the incidence, risk factors, and clinical outcomes of AVN among Chinese children with ALL. METHODS: This study is a retrospective, territory-wide population-based cohort study of pediatric patients with ALL enrolled on one of the three consecutive ALL study protocols (ALL-IC-BFM 2002, CCLG-ALL 2008, and CCCG-ALL 2015). RESULTS: A total of 24 out of 533 pediatric subjects with ALL (4.5%) had symptomatic AVN. Age was the single most important risk factor associated with the development of AVN. Only three patients were below age of 10 at the time of diagnosis of ALL. The incidences of AVN in patients aged above and below 10 years were 18.2% ± 3.6% and 0.8% ± 0.5%, respectively, and were significantly different (p < 0.005). Treatment protocol, immunophenotype, and gender were not predictive of AVN. Among the 24 patients, five required orthopedic interventions in view of progressive and severe disease. For subjects with hip joints involvement, follow-up assessments showed 12 of 22 hip joints had radiological progression over a median duration of 3.63 years. Seventeen of them did not have pain at the latest follow-up and among patients with pain (n = 7), five did not experience any limitation on activities of daily living while two required use of walking aids or wheelchair. CONCLUSION: The incidence of symptomatic AVN in Chinese ALL patients was comparable to other studies in Western population. Adolescent age more than 10 years old was recognized to be the most important factor for development of AVN. Significant proportion of patients had radiological progression over time with a small percentage of subjects had daily activities affected.

Glymphatic system dysfunction in pediatric acute lymphoblastic leukemia without clinically diagnosed central nervous system infiltration: a novel DTI-ALPS method.

BACKGROUND AND OBJECTIVE: Central nervous system (CNS) infiltration commonly occurs in children with acute lymphoblastic leukemia (ALL). Nevertheless, CNS infiltration is rarely detected at the initial diagnosis. The glymphatic system, which regulates cerebrospinal fluid (CSF) and interstitial fluid transport, is considered one of the possible routes of CNS infiltration by leukemia cells. In this study, we used diffusion tensor image analysis along the perivascular space (DTI-ALPS) method to investigate glymphatic system function and obtained CSF volume using synthetic magnetic resonance imaging (SyMRI) in pediatric ALL without clinically diagnosed CNS infiltration. MATERIALS AND METHODS: Twenty-nine ALL and 29 typically developing (TD) children were prospectively recruited (age 4-16 years) in the present study. Group differences in brain volumetric parameters, brain water diffusivities, and the ALPS index were evaluated after controlling for age, gender, and handedness. Furthermore, significant group-different parameters were correlated with clinical information using partial correlations analysis. RESULTS: Lower Dxassoc and ALPS index, and increased CSF volume were found in pediatric ALL (all pFDR-corrected < 0.05). Moreover, the ALPS index was negatively associated with the risk classification (r = - 0.59, pFDR-corrected = 0.04) in pediatric ALL. CONCLUSIONS: Dysfunction of the glymphatic system and accumulation of CSF were presented in pediatric ALL without clinically diagnosed CNS infiltration. These novel findings suggested that the glymphatic system might be essential in the early-stage process of ALL CNS infiltration, which provides a new direction for exploring underlying mechanisms and early detection of pediatric ALL CNS infiltration. KEY POINTS: • Lower Dxassoc and ALPS index, and increased CSF volume were found in pediatric ALL (all pFDR-corrected < 0.05). • The ALPS index was negatively associated with the risk classification (r = -0.59, pFDR-corrected = 0.04) in pediatric ALL. • Dysfunction of the glymphatic system and accumulation of CSF were presented in pediatric ALL without clinically diagnosed CNS infiltration, which suggested that the ALPS index and CSF volume might be promising imaging markers for early detection of pediatric ALL CNS infiltration.

COVID-19 infection during blinatumomab therapy: Is safety a dilemma?

Patients with acute lymphoblastic leukemia may be particularly vulnerable to SARS-CoV-2 infection and severe illness. The mainstay of current treatment is the use of blinatumomab in patients with refractory or relapsed B-cell precursor acute lymphoblastic leukemia. We discuss the case of a patient with relapsed acute lymphoblastic leukemia who became positive for SARS-CoV-2 during blinatumomab therapy. There are no formal recommendations on the decision to continue, withhold, or delay blinatumomab treatment in these patients. More studies exploring this issue are warranted, as SARS-CoV-2 is expected to be here to stay.

Osteoarticular manifestation of acute lymphoblastic leukemia in adults: a literature review.

Osteoarticular manifestations such as arthritis and bone pain are scarce among adults with acute lymphoblastic leukemia (ALL). We present a systematic review of osteoarticular first clinical manifestation related to ALL in adults, and we report a case of an adult patient with a B-cell ALL revealed by refractory pygalgia and arthritis. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline using the MEDLINE database, including case reports and case series describing osteoarticular manifestations revealing ALL in adults. There were 29 patients with osteoarticular manifestations, revealing ALL (including our case). The mean age was 34.00 ± 13.29 years. Osteoarticular manifestations were peripheral articular signs (7 cases), axial manifestations (17 cases), and osteolytic lesions (21 cases). Vertebral fractures were reported in 4 cases. MRI was performed in 15 cases, showing heterogeneous signal changes in the vertebra, skull, and sacroiliac bones. It showed avascular necrosis of the femoral head in one case. PET scan, performed in 7 cases, showed diffuse or localized FDG uptakes in the bone marrow. Hypercalcemia was noted in 9 cases. The treatment was based on chemotherapy (23 patients) and radiotherapy (4 cases). During the follow-up, remission was noted in 14 cases, death in 9 cases, and was not available in 6 patients. Our review showed that axial manifestations, joint swelling, bone pain, and hypercalcemia could be the first and only symptoms of ALL in adults, making the diagnosis of ALL difficult to recognize, leading to a diagnosis delay. Key Points • Acute lymphoblastic leukemia in adults revealed by osteoarticular manifestations can be misdiagnosed as rheumatic diseases. • Axial manifestations, joint swelling, bone pain, and hypercalcemia could be the first and only symptoms of acute lymphoblastic leukemia in adults. • Complete blood count and calcium blood test should be performed as first-line investigations in adults with axial or peripheral articular symptoms. • Physicians should be aware of this clinical presentation to avoid diagnosis delay and improve prognosis.

Measuring disparities in event-free survival among children with acute lymphoblastic leukemia in an academic institute in Oklahoma, 2005-2019.

BACKGROUND: Acute lymphoblastic leukemia (ALL) is the most common type of childhood cancer. While there have been successes in the treatment of leukemia, less information is available on reasons for disparities in event-free survival (EFS) among underserved populations. METHODS: We partnered with a children's hospital at an academic institution to abstract data from the institution's cancer registry, the state cancer registry, and electronic medical records on cancer diagnosis, treatment, and outcomes for children with ALL (n = 275) diagnosed from 2005 to 2019 prior to age 20. We evaluated the relation between 1) race/ethnicity, 2) distance to the children's hospital, and 3) area deprivation with EFS, defined as time from diagnosis to relapse, death, or the end of the study period. We evaluated differences in EFS using Kaplan-Meier analysis with the log-rank test. We used the Cox Proportional Hazards Model for multivariable survival analyses. RESULTS: Most children were diagnosed with ALL under five years of age (45%) and with Pre-B ALL (87%). Twelve percent of children experienced a relapse and 5% died during induction or remission. EFS at 5 years was 82%. Non-Hispanic (NH) Black children had worse, though imprecise, EFS compared to NH White children (Adjusted Hazard Ratio: 2.07, 95% CI: 0.80, 5.38). Children residing in areas with higher deprivation had a higher adjusted hazard of poor outcomes compared to the least deprived areas, though estimates were imprecise (2nd quartile HR: 1.51, 3rd quartile: 1.85, 4th quartile: 1.62). We observed no association between distance to the children's hospital and EFS. CONCLUSION: We observed poorer EFS for NH Black children and children residing in areas with high deprivation, though the estimates were not statistically significant. Our next steps include further evaluating socioeconomic factors in both rural and urban children to identify disparities in outcomes for children with ALL and other childhood cancers.

Predictive Factors and Outcomes after Allogeneic Stem Cell Transplantation for Adults with Acute Lymphoblastic Leukemia in Brazil.

Allogeneic stem cell transplantation (HSCT) remains a potentially curative approach for acute lymphoblastic leukemia (ALL), especially for high-risk patients and those with relapsed/refractory disease, although its efficacy is offset by a not-negligible toxicity. Adult patients with ALL fare worse in developing countries, with little data about the HSCT in this setting. In this study, we aimed to describe outcomes and examine risk factors for overall survival (OS), leukemia-free survival (LFS), cumulative incidence of relapse (CIR), nonrelapse mortality (NRM), and graft-versus-host disease (GVHD) after HSCT for ALL in Brazilian centers. This retrospective registry study included patients with ALL or ambiguous lineage leukemia age >16 years who underwent a first HSCT at 5 Brazilian centers between January 2007 and December 2017. A total of 275 patients were included, with a median age of 31 years (range, 16 to 65 years). Thirty-five percent were Philadelphia chromosome-positive. A matched sibling donor was used in 53%, a matched unrelated donor (MUD) in 19%, a mismatched unrelated donor in 9%, a haploidentical donor in 19%, and umbilical cord blood in 5%. The engraftment failure rate was 1.5%. The 5-year cumulative incidence of acute grade II-IV was 54.2%, and that of chronic GVHD was 26.2%. Five-year CIR and NRM were 28.1% and 34.1%, respectively. Central nervous system involvement at diagnosis (hazard ratio [HR], 2.2) and disease status (HR, 1.8 for second or later complete response and 7.9 for refractory) were associated with increased relapse incidence, whereas the use of peripheral blood graft (HR, .51) and a haploidentical donor (HR, .4) significantly decreased relapse incidence. Five-year OS and LFS were 40.7% (95% confidence interval [CI], 35.1-47.1) and 37.8% (95% CI, 32.3-44.1), respectively. Patient age, donor age, and disease status were independently associated with OS and LFS. Pre-HSCT positivity of minimal residual disease (>.01%) was associated with worse LFS (HR, 1.47) in available cases. This is the largest series of adults with ALL undergoing HSCT from Brazil reported to date. Although OS and LFS were similar to data reported in the literature, NRM was higher. Patient age and donor age outweighed donor type or graft source in our analysis. Interestingly, haploidentical HSCT was associated with lower CIR, whereas the use of MUDs was associated with higher NRM and GVHD rates. These results impact donor selection strategy in Brazil with the aim of offering timely HSCT for high-risk ALL patients in our setting.

Induction-related mortality in adolescents and young adults with acute lymphoblastic leukemia in a resource-limited setting: do treatment-related complications create more impact than disease biology?

BACKGROUND: Acute lymphoblastic leukemia (ALL) is a malignant clonal bone marrow disorder with a high mortality rate during the initial therapy. This retrospective study aimed to describe and analyze the risk factors and causes of induction-related mortality (IRM) in an adolescent and adult ALL population treated in a low- and middle-income country. METHODS: From 2009 to 2016, a total of 167 patients were included, of which 50.9% were male with a median age of 28 years. B-immunophenotype represented 97.6%, and high-risk cytogenetics were present in 23.3%. During induction therapy, 91% had at least 1 complication, most of which were infectious, with an IRM of 12%. RESULTS: Factors associated with increased mortality rate were central nervous system (CNS) status [CNS-3: hazard ratio (HR) 3.029; 95% confidence interval (CI), 0.79‒11.49; P =0.103 and CNS-2: HR, 9.98; 95% CI, 2.65‒37.65; P =0.001] and dialysis requirement (HR, 9.15; 95% CI, 2.44‒34.34; P =0.001). CONCLUSION: Our study confirms that ALL patients treated in resource-constrained settings have high rates of IRM, mainly attributed to advanced disease and high tumor burden at diagnosis.

Epidemiology of Acute Leukemia among Children with Down Syndrome in Korea.

PURPOSE: Children with Down syndrome (DS) show a higher risk of acute leukemia than those without DS. In this study, we investigated the nationwide incidence of acute leukemia among children with DS and compared their epidemiologic characteristics with those of children with acute leukemia but without DS. MATERIALS AND METHODS: Using the National Health Insurance Service database, we selected patients with acute leukemia aged 0-19 years at diagnosis between 2007 and 2016. RESULTS: Among the 4,697 children with acute leukemia, 54 (1.1%) had DS. The median incidence rate of leukemia with DS by year was 1.3% (range, 0.2%-2.0%). Sixteen patients with acute lymphoblastic leukemia (ALL; 29.6%) and 36 with acute myeloid leukemia (AML; 66.7%) had DS. The DS group showed younger age at diagnosis than the non-DS group, and diagnosis of AML was more frequent in the DS group than in the non-DS group (3 years vs. 9 years, p<0.001; 66.7% vs. 32.4%, P<0.001, respectively). The 5-year overall survival was comparable between the DS and non-DS groups (88.0% vs. 81.9%, p=0.375). Among all the Koreans born between 2007 and 2008, the incidences of acute leukemia, ALL, and AML were 49.25, 20.75, and 163.38 times higher, respectively, in the DS group than in the non-DS group. CONCLUSION: Our findings support the fact that the incidence of acute leukemia is higher among patients with DS than among those without DS in Korea. However, the DS and non-DS groups in this study had a comparable overall survival rate.

Progress of molecular markers in adult acute B-lymphoblastic leukemia / 白血病·淋巴瘤

Acute lymphoblastic leukemia (ALL) is a malignant tumor dominated by B-cell or T-cell proliferation, of which 80% is the malignant proliferation of B-lymphocytes, and it can be more commonly seen in children. Studies have found that ALL is often accompanied by abnormal molecular biological phenotypes. The study of the molecular biological characteristics of ALL helps the precise diagnosis, prognostic analysis, pathogenesis research and the discovery of new diagnostic markers and therapeutic targets. This article summarizes several molecular markers of adult acute B-lymphoblastic leukemia discovered in recent years, and reviews the clinical significance.

IL3-IGH fusion gene-positive pediatric acute lymphoblastic leukemia with hypereosinophilia as the first presentation: report of 1 case and review of literature / 白血病·淋巴瘤

Objective:To investigate the clinical characteristics and prognosis of IL3-IGH fusion gene-positive pediatric acute lymphoblastic leukemia (ALL) with hypereosinophilia as the first presentation.Methods:The clinical data of 1 pediatric IL3-IGH fusion gene-positive ALL patient with hypereosinophilia as the first presentation in January 2021 in Fujian Medical University Union Hospital was retrospectively analyzed and relevant literature was reviewed.Results:This 11-year-old male patient underwent bone marrow examination, and results showed that the proportion of eosinophils was increased; immunophenotyping disclosed that there were about 49.4% abnormal naive B lymphocytes in bone marrow; 43 leukemia fusion genes showed all negative; the whole transcriptome sequencing showed IL3-IGH fusion gene-positive. The patient was finally diagnosed as B-ALL with IL3-IGH fusion gene. According to the Chinese Children Cancer Group (CCCG)-ALL 2020 regimen, eosinophils returned to normal after induction therapy. Bone marrow examination on day 19 of induction showed that the proportion of promyelocytes was 0.005, the proportion of eosinophils was 0.05, and the minimal residual disease (MRD) was 23.02%. Bone marrow examination on day 46 of induction showed remission, and MRD was 0.18%. Consolidation chemotherapy used CAT (cyclophosphamide 1 g/m 2 once; cytarabine 50 mg/m 2, 12 h once, 7 days in total; mercaptopurine 40 mg/m 2, once per night, 7 days in total) regimen. Then the patient was added with lusotinib (75 mg 12 h once) orally and continued to receive high-dose methotrexate (5 g/m 2) regimen chemotherapy for 2 courses, the MRD was 0.20%. Chimeric antigen receptor T-cell (CAR-T) regimen was administered, followed by negative MRD. Conclusions:IL3-IGH fusion gene ALL is more frequently found in males, and more common in older children and young adults. It is prone to organ infiltration damage, and it has a high rate of induction failure and recurrence as well as poor prognosis.

Molecular genetic and clinical characteristics of MEF2D-BCL9 fusion gene-positive acute B-cell lymphoblastic leukemia / 白血病·淋巴瘤

Objective:To investigate the molecular genetic and clinical characteristics of MEF2D-BCL9 fusion gene-positive acute B-cell lymphoblastic leukemia (B-ALL), and to provide the reference for the diagnosis and treatment of the disease.Methods:The medical record and experimental examination data of a 18-year-old female MEF2D-BCL9 fusion gene-positive B-ALL patient were retrospectively analyzed. The clinical manifestations and biological characteristics of MEF2D-BCL9 fusion gene-positive B-ALL were summarized.Results:This 18-year-old female patient was treated in a local hospital in December 2018 and was diagnosed as B-ALL. She achieved complete remission after chemotherapy and recurred at 6 months after the initial onset, and then she was admitted to Hebei Yanda Ludaopei Hospital in the 9 months after the initial onset.MEF2D-BCL9 fusion gene was detected through RNA-sequencing (RNA-seq) and verified by using polymerase chain reaction and Sanger sequencing. Bone marrow cell morphology was similar to mature B cells with vacuoles but without characteristic chromosome karyotype abnormalities. The patient achieved remission after VLD regimen chemotherapy, chimeric antigen receptor T-cell (CAR-T) therapy and bridged to allogeneic hematopoietic stem cell transplantation (allo-HSCT). She has maintained complete remission for 2 years at the last follow-up in February 2022.Conclusions:MEF2D-BCL9 fusion gene-positive B-ALL is characterized with high risk, early relapse and poor prognosis. These patients may benefit from CAR-T and allo-HSCT. It further emphasizes the importance of taking MEF2D-BCL9 fusion gene into the detection or identification by using RNA-seq, particularly for those newly diagnosed B-ALL patients in children and adolescents with specific bone marrow morphology.

Levocarnitine for pegaspargase-induced hepatotoxicity in older children and young adults with acute lymphoblastic leukemia.

BACKGROUND: Pegaspargase (PEG-ASP) is an integral component of therapy for acute lymphoblastic leukemia (ALL) but is associated with hepatotoxicity that may delay or limit future therapy. Obese and adolescent and young adult (AYA) patients are at high risk. Levocarnitine has been described as potentially beneficial for the treatment or prevention of PEG-ASP-associated hepatotoxicity. METHODS: We collected data for patients age ≥10 years who received levocarnitine during induction therapy for ALL, compared to a similar patient cohort who did not receive levocarnitine. The primary endpoint was conjugated bilirubin (c.bili) >3 mg/dl. Secondary endpoints were transaminases >10× the upper limit of normal and any Grade ≥3 hepatotoxicity. RESULTS: Fifty-two patients received levocarnitine for prophylaxis (n = 29) or rescue (n = 32) of hepatotoxicity. Compared to 109 patients without levocarnitine, more patients receiving levocarnitine were obese and/or older and had significantly higher values for some hepatotoxicity markers at diagnosis and after PEG-ASP. Levocarnitine regimens varied widely; no adverse effects of levocarnitine were identified. Obesity and AYA status were associated with an increased risk of conjugated hyperbilirubinemia and severe transaminitis. Multivariable analysis identified a protective effect of levocarnitine on the development of c.bili >3 mg/dl (OR 0.12, p = 0.029). There was no difference between groups in CTCAE Grade ≥3 hepatotoxicity. C.bili >3 mg/dl during induction was associated with lower event-free survival. CONCLUSIONS: This real-world data on levocarnitine supplementation during ALL induction highlights the risk of PEG-ASP-associated hepatotoxicity in obese and AYA patients, and hepatotoxicity's potential impact on survival. Levocarnitine supplementation may be protective, but prospective studies are needed to confirm these findings.

Pediatric-inspired regimen with late intensification and increased dose of L-asparaginase for adult acute lymphoblastic leukemia: the KALLA 1406/1407 study.

BACKGROUND/AIMS: The objective of this study was to evaluate the efficacy and feasibility of the pediatric-inspired regimen of the adult acute lymphoblastic leukemia (ALL) Working Party, the Korean Society of Hematology. METHODS: Data of 99 patients with newly diagnosed ALL, who were treated with the KALLA 1406/1407 protocol, were retrospectively analyzed. All patients equally received age-adjusted daunorubicin, vincristine, and prednisolone. L-asparaginase was additionally administered to Philadelphia (Ph)-negative patients according to age, whereas Ph-positive patients received 600 mg/day of imatinib. RESULTS: A total of 99 patients were enrolled in this study, of whom 62 (62.6%) were diagnosed with Ph-negative ALL and 37 (37.3%) were diagnosed with Ph-positive ALL. The median age of patients in the Ph-negative ALL group was 46 years, and that of patients in the Ph-positive ALL group was 49 years. In patients with Ph-negative ALL, 57 (92%) patients achieved complete remission (CR) and CR with incomplete hematologic recovery (CRi). Disease-free survival (DFS) and overall survival (OS) rates at 2 years were estimated to be 42% and 63%, respectively. In patients with Ph-positive ALL, 32 (86%) patients achieved CR/CRi, and 2-year DFS and OS were 31.2% and 49.1%, respectively. Patients who were able to proceed to the allogeneic hematopoietic cell transplantation and younger patients showed significantly superior survival in both Ph-negative ALL and Ph-positive ALL. Neutropenic fever and bacterial infection were the most common and severe adverse events. CONCLUSION: The KALLA 1406/1407 protocol showed tolerable toxicities in adult ALL patients. Especially, younger patients had more survival benefits with KALLA 1406/1407 protocol.

Quimioterapia intensiva asociada a imatinib en leucemia linfoblástica aguda del adulto, Philadelphia positivo. Experiencia en un hospital público / Intensive chemotherapy with tyrosine kinase inhibitors in philadelphia-positive acute lymphoblastic leukemia

Background: Before the advent of tyrosine kinase inhibitors (TKIs), patients with Philadelphia-positive Acute Lymphoblastic Leukemia (Ph+ALL) had a poor prognosis. The association of TKIs to intensive chemotherapy (CT) improved outcome. Aim: To evaluate results of an intensive CT protocol including TKI in a public hospital in Santiago, Chile. Material and Methods: All patients with Ph+ALL diagnosed between January 2010 and February 2019, and who met inclusion criteria for intensive CT, received the Ph+ALL national protocol in association with imatinib and were included in this analysis. Results: Thirty-five patients aged 15 to 59 years received treatment. Complete response (CR) was obtained in 97%. Measurable residual disease (MRD) was negative in 61% (19/31 evaluable cases) during follow-up, and 55% (16/29) were MRD (-) before three months. Relapse was observed in 13 cases. Three patients underwent allogeneic hematopoietic stem cell transplant (HSCT), two in CR1. The overall survival (OS) and event-free survival (EFS) at three years were 52 and 34%, respectively. In patients who achieved MRD negativity before three months, no statistically significant differences in OS (64 and 42% respectively, p = 0.15) or EFS (35 and 32% respectively, p = 0.37) were observed. Conclusions: The prognosis of Ph+ALL improved with the association of imatinib to intensive CT. MRD-negative status before three months in this series was not significantly associated with better outcomes. Our series suggests that the Ph+ALL national protocol associated to TKI is a therapeutic alternative with high CR and aceptable MRD (-) rates.

[The pathological diagnosis and differential diagnosis of hematopoietic cell tumors of ambiguous lineage].

Objective: To explore the key points of the pathological and differential diagnoses of extra-medullary masses of hematopoietic cell tumors of ambiguous lineage, and to discuss the possible solutions. Methods: Five hematopoietic cell tumors of ambiguous lineage cases were collected, including myeloid sarcoma, mixed phenotype acute leukemia, B/myeloid, T-lymphoblastic lymphoma combined with acute myeloid leukemia, acute undifferentiated leukemia with cutaneous MPDCP and early T-precursor cell acute lymphoblastic leukemia. The data including morphology, immunostaining, and flow cytometry analysis were collected, and we explored the problems and differential diagnosis in the diagnosis of hematopoietic cell tumors of ambiguous lineage. Results: The five cases showed that the accurate pathological diagnosis and classification of hematopoietic cell tumors of ambiguous lineage should be based on lineage-specific antigens. Moreover, tumor cells have the potential of multi-directional differentiation. In different sites or different periods, the differentiation of tumor cells may be different. Biopsy and detection of all related markers should be performed for the initial diagnosis, and the detection should be repeated when the condition of the patient changes. Combined application of multi-techniques, including morphology and flow cytometry analysis, is recommend for the diagnosis of hematopoietic cell tumors of ambiguous lineage, since the conventional morphology and immunophenotyping methods are limited. Conclusion: Hematopoietic cell tumors of ambiguous lineage are derived from hematopoietic stem cells with a potential of multi-differentiation. The differentiation of tumor cells is variable. We need to integrate cell morphology, flow cytometry, pathology, clinical data, and molecular genetics to make a comprehensive diagnosis.

Differing Outcomes of Patients with High Hyperdiploidy and ETV6-RUNX1 Rearrangement in Korean Pediatric Precursor B Cell Acute Lymphoblastic Leukemia.

PURPOSE: Recent cooperative trials in pediatric acute lymphoblastic leukemia (ALL) report long-term event-free survival (EFS) of greater than 80%. In this study, we analyzed the outcome and prognostic factors for patients with precursor B cell ALL (n=405) diagnosed during a 10-year period (2005-2015) at our institution. MATERIALS AND METHODS: All patients were treated with a uniform institutional regimen based on four risk groups, except for steroid type; patients diagnosed up till 2008 receiving dexamethasone, while subsequent patients received prednisolone. None of the patients received cranial irradiation in first complete remission. RESULTS: The 10-year EFS and overall survival was 76.3%±2.3% and 85.1%±1.9%. Ten-year cumulative incidence of relapse, any central nervous system (CNS) relapse and isolated CNS relapse was 20.8%±2.2%, 3.7%±1.1%, and 2.5%±0.9%, respectively. A comparison of established, good prognosis genetic abnormalities showed that patients with high hyperdiploidy had significantly better EFS than those with ETV6-RUNX1 rearrangement (10-year EFS of 91.2%±3.0% vs. 79.5%±4.4%, p=0.033). For the overall cohort, male sex, infant ALL, initial CNS involvement, and Philadelphia chromosome (+) ALL were significant factors for lower EFS in multivariate study, while high hyperdiploidy conferred favorable outcome. For high and very high risk patients (n=231), high hyperdiploidy was the only significant factor for EFS in multivariate study. CONCLUSION: Regarding good prognosis genetic abnormalities, patients with high hyperdiploidy had significantly better outcome than ETV6-RUNX1 (+) patients. High hyperdiploidy was a major, favorable prognostic factor in the overall patient group, as well as the subgroup of patients with higher risk.