An atypical promyelocytic sarcoma and pleural effusion in a patient with Gorham's disease: Efficiency of ATRA/ATO-based treatment.

Key Clinical Message: This is the first case of a promyelocytic sarcoma diagnosed on pleural effusion and exposed the difficulty of demonstrating a leukemic phase in patients with bone diseases, such as Gorham's disease. It also showed that promyelocytic sarcoma can be treated by ATRA/ATO-based therapy with an efficient and tolerated response. Abstract: Myeloid sarcoma (MS) is a rare extramedullary tumoral infiltration of immature myeloid cells and can occur in different sites of the body, without leukemic infiltration. A 38-year-old woman patient presented at emergency with a pleural effusion, bicytopenias, and Gorham's disease, a very rare bone disorder. In the following days, she worsened with a chylothorax and pancytopenias. Pleural puncture cytologically revealed promyelocytes with Auer rods. Cytogenetic and molecular analyses subsequently confirmed the presence of the t(15:17) translocation. However, no circulating phase of these atypical promyelocytes was found. Similarly, no other origin was identified. We conclude that the patient had a MS of unknown etiology in the form of a pleural effusion with pathological promyelocytes. The patient was treated with a combination of oral all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) with a cytological and molecular remission persisting 3 months after diagnosis. We report here the first case of a promyelocytic MS of pleural origin without concomitant evidence of acute promyelocytic leukemia. We also show the efficacy of ATRA/ATO treatment in this etiology.

Molecular Heterogeneity of Pediatric AML with Atypical Promyelocytes Accumulation in Children-A Single Center Experience.

Acute promyelocytic leukemia (APL) pathogenesis is based on RARA gene translocations, which are of high importance in the diagnosis of and proper therapy selection for APL. However, in some cases acute myeloid leukemia (AML) demonstrates APL-like morphological features such as atypical promyelocytes accumulation. This type of AML is characterized by the involvement of other RAR family members or completely different genes. In the present study, we used conventional karyotyping, FISH and high-throughput sequencing in a group of 271 de novo AML with atypical promyelocytes accumulation. Of those, 255 cases were shown to carry a typical chromosomal translocation t(15;17)(q24;q21) with PML::RARA chimeric gene formation (94.1%). Other RARA-positive cases exhibited cryptic PML::RARA fusion without t(15;17)(q24;q21) (1.8%, n = 5) and variant t(5;17)(q35;q21) translocation with NPM1::RARA chimeric gene formation (1.5%, n = 4). However, 7 RARA-negative AMLs with atypical promyelocytes accumulation were also discovered. These cases exhibited TBL1XR1::RARB and KMT2A::SEPT6 fusions as well as mutations, e.g., NPM1 insertion and non-recurrent chromosomal aberrations. Our findings demonstrate the genetic diversity of AML with APL-like morphological features, which is of high importance for successful therapy implementation.

Coexpression of CD71 and CD117 Identifies an Early Unipotent Neutrophil Progenitor Population in Human Bone Marrow.

Neutrophils are the most abundant peripheral immune cells and thus, are continually replenished by bone marrow-derived progenitors. Still, how newly identified neutrophil subsets fit into the bone marrow neutrophil lineage remains unclear. Here, we use mass cytometry to show that two recently defined human neutrophil progenitor populations contain a homogeneous progenitor subset we term "early neutrophil progenitors" (eNePs) (Lin-CD66b+CD117+CD71+). Surface marker- and RNA-expression analyses, together with in vitro colony formation and in vivo adoptive humanized mouse transfers, indicate that eNePs are the earliest human neutrophil progenitors. Furthermore, we identified CD71 as a marker associated with the earliest neutrophil developmental stages. Expression of CD71 marks proliferating neutrophils, which were expanded in the blood of melanoma patients and detectable in blood and tumors from lung cancer patients. In summary, we establish CD117+CD71+ eNeP as the inceptive human neutrophil progenitor and propose a refined model of the neutrophil developmental lineage in bone marrow.

Leucemia promielocítica aguda M3. Reporte de un caso clínico / Acute promyelocytic leukemia M3. Report of a clinical case

La leucemia es una neoplásica hemática que contiene múltiples subtipos, entre ellos la leucemia promielocítica aguda, caracterizada por la multiplicación clonal del linaje mieloide y eritroide. El presente caso pertenece a un paciente masculino de 20 años, sin antecedentes de importancia y con un cuadro evolutivo de 20 días con sangrado del dedo anular de la mano derecha, y con ausencia de proceso cicatricial. A partir de los exámenes de laboratorio se identifica bicitopénia eritroide y plaquetaria, con evidencia de un 93% de promielocitos. El tratamiento con ATO, ATRA y Antraciclinas logró una leve mejoría. Durante su estadía hospitalaria desarrolló síndrome de diferenciación, lo que ocasionó su fallecimiento.

Leukemia is a hematic neoplastic that contains multiple subtypes, including acute promyelocytic leukemia, characterized by the clonal multiplication of the myeloid and erythroid lineage. The present case belongs to a 20-year-old male patient without health history of importance and with a 20-day evolutionary picture with bleeding from the ring finger of his right hand, and without scarring process. Erythroid and platelet bicytopenia is identified from laboratory tests with evidence of 93% promyelocytes. The treatment including ATO, ATRA and Anthracyclines achieved a slight improvement. He developed differentiation syndrome during hospitalization, which caused his death.

Impact of Di(2-ethylhexyl)phthalate on migration rate of human promyelocytic leukemia cells (HL-60).

INTRODUCTION: Softeners like phthalate esters are ubiquitous in the environment and have been detected in transfusion bags, though there is only a limited amount of studies on the effect of phthalates on blood cells. This study seeks to determine effects on cell migration of human promyelocytic leukemia cells (HL-60) incubated with di(2-ethylhexyl)phthalate (DEHP) at concentrations found in blood bags. MATERIAL AND METHODS: HL-60 cells were incubated with DEHP concentrations ranging from 0.1 µg/ml to 1000 µg/ml, diluted in DMSO, over 24 h, 48 h, and 72 h. Migration rate was analyzed along an SDF-1α gradient using Transwell migration inserts. RESULTS: Of the applied concentrations 100 µg/ml, 250 µg/ml, 500 µg/ml, and 1000 µg/ml showed a significant decrease in migration rates relative to DMSO control at all measuring points (p < 0.05), with relative migration rates between 37.87 % for 100 µg/ml and 25.34 % for 1000 µg/ml relative to DMSO after 24 h of stimulation and 19.73 % for 100 µg/ml and 14.69 % for 1000 µg/ml respectively after 72 h of incubation. CONCLUSION: Our results indicate HL-60 to be a suitable in vitro model for examining effects of DEHP on the migration of blood and nucleated cells at concentrations found in blood bags.

Differentiation and characterization of myeloid cells.

Ex vivo differentiation of myeloid cells begins with an enriched population of bone marrow-derived hematopoietic stem cells generated by lineage depletion and/or positive selection for CD34(+) antigen (human) or Sca-1(+) (mouse) cells, which are then expanded and subsequently induced in vitro in a process that recapitulates normal myeloid development. Myeloid cell lines include two human leukemic cell lines, NB-4 and HL-60, which have been demonstrated to undergo retinoic acid-induced myeloid development; however, both cell lines exhibit defects in the up-regulation of late-expressed neutrophil-specific genes. Multiple murine factor-dependent cell models of myelopoiesis are also available that express the full range of neutrophil maturation markers, including: 32Dcl3 cells, which undergo G-CSF-induced myeloid maturation; EML/EPRO cells, which develop into mature neutrophils in response to cytokines and retinoic acid; and ER-Hoxb8 cells, which undergo myeloid maturation upon removal of estradiol in the maintenance medium. In this unit, the induction of myeloid maturation in each of these model systems is described, including their differentiation to either neutrophils or macrophages, if applicable. Commonly used techniques to test for myeloid characteristics of developing cells are also described, including flow cytometry and real time RT-PCR.

Clinical and laboratory features of seven patients with acute myeloid leukemia (AML)-M2/M3 and elevated myeloblasts and abnormal promyelocytes.

BACKGROUND: There is limited information on a special subtype of Acute myeloid leukemia (AML) characterized by >20% myeloblasts and >20% abnormal promyelocytes in bone marrow and peripheral blood. OBJECTIVE: The objective of the present investigation was to explore the clinical and laboratory features of seven patients with AML-M2/M3. METHOD: We retrospectively assessed cell morphology, cytochemistry, immunophenotype, cytogenetics, and clinical features of seven patients with this rare subtype of AML. RESULTS: All seven cases had thrombocytopenia, coagulation abnormalities, >20% myeloblasts and abnormal promyelocytes. The PML/RARα fusion gene was present in six patients and two patients presented a mixed PML/RARα and AML1/ETO genotype. Five cases achieved CR and two cases did not achieve remission and one case transform into AML-M2 after CR1. CONCLUSIONS: The clinical and laboratory features of seven patients with AML-M2/M3 are demonstrated in the present study, providing information on the FAB sub-classification.

ZBTB16-RARα variant of acute promyelocytic leukemia with tuberculosis: a case report and review of literature.

A 23-year-old male presented with pulmonary tuberculosis and swelling of both lower limbs. He was put on antitubercular treatment. Hemogram showed mild anemia and Pseudo Pelger-huet cells. The bone marrow (BM) examination showed 52% promyelocytes with regular round to oval nuclei, few granules and were positive for CD13 and CD33, and negative for HLA-DR. Cytogenetic analysis of the BM aspirate revealed an apparently balanced t(11;17)(q23;q21). Final diagnosis rendered was acute promyelocytic leukemia (APL) with t(11;17)(q23;q21); ZBTB16/RARA. APL is a distinct subtype of acute myeloid leukemia. The variant APL with t(11;17)(q23;q21) cases that are associated with the ZBTB16/RARA fusion gene have been reported as being resistant to all-trans-retinoic acid (ATRA). Therefore, differential diagnosis of variant APL with t(11;17)(q23;q12) from classical APL with t(15;17)(q22;q12); PML-RARA is very important. Here we have discussed the importance of distinct morphology of variant APL and also significance of rare presentation with tuberculosis.

ZBTB16-RARalpha variant of acute promyelocytic leukemia with tuberculosis: a case report and review of literature / 대한혈액학회지

A 23-year-old male presented with pulmonary tuberculosis and swelling of both lower limbs. He was put on antitubercular treatment. Hemogram showed mild anemia and Pseudo Pelger-huet cells. The bone marrow (BM) examination showed 52% promyelocytes with regular round to oval nuclei, few granules and were positive for CD13 and CD33, and negative for HLA-DR. Cytogenetic analysis of the BM aspirate revealed an apparently balanced t(11;17)(q23;q21). Final diagnosis rendered was acute promyelocytic leukemia (APL) with t(11;17)(q23;q21); ZBTB16/RARA. APL is a distinct subtype of acute myeloid leukemia. The variant APL with t(11;17)(q23;q21) cases that are associated with the ZBTB16/RARA fusion gene have been reported as being resistant to all-trans-retinoic acid (ATRA). Therefore, differential diagnosis of variant APL with t(11;17)(q23;q12) from classical APL with t(15;17)(q22;q12); PML-RARA is very important. Here we have discussed the importance of distinct morphology of variant APL and also significance of rare presentation with tuberculosis.