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Lymphoblasts with Auer rod – like inclusions in a case of paediatric B lymphoblastic leukemia
Author(s) -
Gupta Anurag,
Reddy G. Krishna,
Nalla Nagaraju,
Goyal Manu
Publication year - 2017
Publication title -
pediatric blood and cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.116
H-Index - 105
eISSN - 1545-5017
pISSN - 1545-5009
DOI - 10.1002/pbc.26392
Subject(s) - hematopathology , medicine , molecular genetics , library science , genetics , biology , cytogenetics , computer science , gene , chromosome
To The Editor: A 5 year old male on treatment with steroids and methotrexate for idiopathic rheumatoid arthritis was determined to have anaemia and thrombocytopenia without organomegaly or lymphadenopathy. Peripheral blood (PB) smear revealed 43% blasts with <1% blasts showing presence of Auer-rod-like intracytoplasmic inclusions (ARLI) (Fig. 1). Myeloperoxidase cytochemistry was negative. Flow cytometry was consistent with B-lymphoblastic leukemia with blasts expressing CD34, CD19, CD10, CD22, CD38, CD79a, and HLA-DR and negative for CD45, CD20, CD2, cytoplasmic CD3, CD5, CD7, CD13, CD33, CD117 and myeloperoxidase. Cytogenetics revealed hyperdiploidy with karyotype reported as 56,XY,+X,+4,+5,der(5)t(5;5)(q22;q13),+6,+8,+10,+14,+17,+18,+21 [2]/57,idem,+21[13]/58,+X,+4,+5,+5,+6,+8,+10,+14,+17,+18,+21,+ 21[4]/46,XY[1]. The patient was treated on a good risk BerlinFrankfurt-Münster (BFM) protocol. Day 35 bone marrow showed complete morphological remission. The patient is alive and currently under follow-up. Auer rods, first described by JohnAuer, are rod-shaped peroxidasepositive intracytoplasmic structures formed by aggregation and concentration of the peroxidase granules in the leukemic blasts and are diagnostic of myeloid differentiation.1–3 Auer rods are seen in M1 to M6 French-American-British classification of acute myeloid leukemia (AML), most commonly associated with AML-M3.4 These have also been reported in immature myeloid cells from PB of normal human foetuses.5 ARLI in lymphoid cells have been described rarely in chronic lymphocytic leukemia, prolymphocytic leukemia, multiple myeloma, follicular lymphoma and peripheral marginal zone lymphoma. These inclusions on electron microscopy were found to be swollen mitochondria or immunoglobulins.6–9 Round to oval intracytoplasmic inclusions resemblingmicrotubules, lysosomes, ribosomal-lamellar complexes, viral particles, and mitochondria have been reported in acute lymphoblastic leukemia (ALL).10 However, ARLI inB-lymphoblasts havebeen reportedonly in two cases of adult ALL11,12: a 28 year old female with 80% blasts in bone marrow and a 27 year old male with 83% blasts in PB. Rare blasts showed ARLI in both cases, which were peroxidase and Sudan black-B positive in former and negative in the latter.11,12 Except for terminal deoxynucleotidyl transferase (TdT), immunophenotyping was not available for the former case11; hence the possibility of myeloid phenotype can-