title: Mixed-phenotypic acute leukemia series from tertiary care center.
abstract: BACKGROUND
  Mixed-phenotype acute leukemias (MPALs) are a heterogeneous group of rare leukemias constituting approximately 2%-5% of all leukemias, in which assigning a single lineage of origin is not possible. They are diagnosed by either the presence of antigens of more than one lineage or by the presence of dual population of blasts belonging to two or more lineages. We highlight the clinicopathological, immunophenotype, and genetic data of a cohort (n = 14) of patients diagnosed and treated at our center.
  
  
  METHODS
  We retrospectively analyzed consecutive cases of MPAL diagnosed in our flow cytometry laboratory from May 2012 to August 2015. These cases were diagnosed based on immunophenotyping of peripheral blood/bone marrow aspirates and morphology/genetics wherever available as per the World Health Organization (WHO) 2008 guideline.
  
  
  RESULTS
  Among 628 consecutive acute leukemia (AL) cases diagnosed and evaluated during this period, we identified 14 (2.2%) patients with MPAL fulfilling WHO 2008/EGIL criteria for immunological characterizing of AL criteria. Majority of these were males (n = 8, male:female ratio 1.3:1) and adults (n = 11, 78.5%). The median age of this cohort was 41 years (range 2-80). These cases were further classified as: B/myeloid (n = 9), T/myeloid (n = 4), and B/T MPAL (n = 1). Cytogenetics was available in 12 out of 14 cases, out of which, three cases had normal karyotype, three with t(9;22)(q34;q11), and two cases with complex karyotype. We also came across a rare case of B + T lymphoid MPAL who had mixed-lineage leukemia gene t(v; 11q23) rearrangement.
  
  
  CONCLUSIONS
  MPAL is a complex entity with heterogeneous clinical, immunophenotypic, cytogenetic, and molecular features. Multiparametric flowcytometry by using comprehensive antibody panels is a valuable tool for diagnosis. Subsequent cytogenetic and molecular analysis for further prognostic stratification and treatment modalities are important.
authors.affiliation: Department of Laboratory Haematology and Molecular Genetics, Tata Medical Centre, Kolkata, West Bengal, India.
authors.forename: Ravikiran N
authors.initials: RN
authors.lastname: Pawar
authors.affiliation: Department of Laboratory Haematology and Molecular Genetics, Tata Medical Centre, Kolkata, West Bengal, India.
authors.forename: Sambhunath
authors.initials: S
authors.lastname: Banerjee
authors.affiliation: Department of Laboratory Haematology and Molecular Genetics, Tata Medical Centre, Kolkata, West Bengal, India.
authors.forename: Subhajit
authors.initials: S
authors.lastname: Bramha
authors.affiliation: Department of Clinical Haematology, Tata Medical Centre, Kolkata, West Bengal, India.
authors.forename: Shekhar
authors.initials: S
authors.lastname: Krishnan
authors.affiliation: Department of Clinical Haematology, Tata Medical Centre, Kolkata, West Bengal, India.
authors.forename: Arpita
authors.initials: A
authors.lastname: Bhattacharya
authors.affiliation: Department of Clinical Haematology, Tata Medical Centre, Kolkata, West Bengal, India.
authors.forename: Vaskar
authors.initials: V
authors.lastname: Saha
authors.affiliation: Department of Pediatric Oncology, Tata Medical Centre, Kolkata, West Bengal, India.
authors.forename: Anupam
authors.initials: A
authors.lastname: Chakrapani
authors.affiliation: Department of Pediatric Oncology, Tata Medical Centre, Kolkata, West Bengal, India.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Bhave
authors.affiliation: Department of Pediatric Oncology, Tata Medical Centre, Kolkata, West Bengal, India.
authors.forename: Mammen
authors.initials: M
authors.lastname: Chandy
authors.affiliation: Department of Pediatric Oncology, Tata Medical Centre, Kolkata, West Bengal, India.
authors.forename: Reena
authors.initials: R
authors.lastname: Nair
authors.affiliation: Department of Laboratory Haematology and Cytognetics, Tata Medical Centre, Kolkata, West Bengal, India.
authors.forename: Mayur
authors.initials: M
authors.lastname: Parihar
authors.affiliation: Department of Laboratory Haematology and Molecular Genetics, Tata Medical Centre, Kolkata, West Bengal, India.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Arora
authors.affiliation: Department of Laboratory Haematology and Molecular Genetics, Tata Medical Centre, Kolkata, West Bengal, India.
authors.forename: D K
authors.initials: DK
authors.lastname: Mishra
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001773:Blood Cells; D001853:Bone Marrow / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D015456:Leukemia, Biphenotypic, Acute / Q000175:diagnosis* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D062606:Tertiary Care Centers; D055815:Young Adult