Pediatric Acute Lymphoblastic Leukemia Workup
- Author: Vikramjit S Kanwar, MBBS, MBA, MRCP(UK), FAAP; Chief Editor: Jennifer Reikes Willert, MD more...
Upon initial evaluation, obtain a complete blood cell (CBC) count. A hematologist or hematopathologist must evaluate the peripheral smear for the presence and morphology of lymphoblasts. An elevated leukocyte count of more than 10 × 109/L (>10 × 103/µL) occurs in one half of patients with acute lymphoblastic leukemia (ALL). Neutropenia, anemia, and thrombocytopenia are often observed secondary to inhibition of normal hematopoiesis by leukemic infiltration. It is important to recognize that 20% of patients with ALL initially present with pancytopenia and no evidence of peripheral blasts.
Various metabolic abnormalities may include increased serum levels of uric acid, potassium, phosphorus, calcium, and lactate dehydrogenase (LDH). The degree of abnormality reflects the leukemic cell burden and destruction (lysis). Although not universally performed, coagulation studies can be helpful in patients with T-lineage ALL and should include tests of the prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen level, and D-dimer level to assess for disseminated intravascular coagulation (DIC).
No other imaging studies than chest radiography to evaluate for a mediastinal mass should be required. However, if the physical examination reveals enlarged testes, perform ultrasonography to evaluate for testicular infiltration. In addition, if anthracyclines are to be administered, obtain a baseline echocardiogram and an electrocardiogram (ECG).
To assess for central nervous system (CNS) involvement and to administer intrathecal chemotherapy, lumbar puncture with cytospin morphologic analysis is performed before systemic chemotherapy is administered. Due to increased risk of relapse with a traumatic lumbar puncture, it should be performed by an experienced pediatric oncologist in patients with adequate platelet counts.
Acute lymphoblastic leukemia (ALL) cells rearrange their immunoglobulin and T-cell receptor (TCR) genes and express antigen receptor molecules in ways that correspond to such processes in normal developing B and T lymphocytes, so that ALL can be classified as B-lineage or T-lineage ALL.
Mature B-cell ALL should be differentiated from other B-lineage ALL and accounts for only 1-3% of childhood ALL. Diagnosis depends on the detection of surface immunoglobulin on leukemic blasts, as well as distinctive morphology, with deeply basophilic cytoplasm containing prominent vacuoles, designated L3 in the French-American-British (FAB) system (see Histologic Features).
B-lineage ALL accounts for 80% of childhood ALL and involves lymphoblasts that have cell-surface expression of 2 or more B-lineage–associated antigens (ie, CD19, CD20, CD24, CD22, CD21, or CD79). CD10 is commonly expressed, which makes it a useful diagnostic marker, and the presence of aberrant myeloid markers (eg, CD7) is occasionally noted but has little prognostic impact. B-cell precursors of ALL can be further subclassified as early pre–B-cell, pre–B-cell, or transitional pre–B-cell, but distinguishing these subtypes is usually not clinically relevant.
T-lineage ALL accounts for 10-15% of childhood ALL, and is identified by the expression of T-cell–associated surface antigens, of which cytoplasmic CD3 is specific. T-cell ALL cases can be classified by early, mid, or late thymocytes, and 10% of cases are early T-precursor (ETP) ALL characterized by absent CD1a and CD8, weak CD5, and one or more myeloid or stem cell markers (eg, CD117, CD34, CD13, CD33). ETP ALL is thought to have worse prognosis, but this assumption may not be valid on modern T-cell ALL chemotherapy protocols.
The overall outcome for T-lineage and high risk B-lineage ALL is similar, provided intensive chemotherapy is used.
Cytogenetic and Molecular Studies
In 80% of pediatric acute lymphoblastic leukemia (ALL) cases, specific genetic alterations can be found in leukemic blasts using routine karyotype analysis and molecular techniques, such as fluorescence in situ hybridization (FISH), reverse transcriptase-polymerase chain reaction (RT-PCR), and Southern blot analysis. Important diagnostic, therapeutic, and prognostic implications are associated with the abnormalities described.
See Acute Lymphoblastic Leukemia Staging for summarized information.
B-lineage ALL has a variety of chromosomal abnormalities, which in almost half of cases confer favorable outcomes:
t(12;21)(p13;q22) or ETV6-RUNX1 (formerly known as TEL-AML1) (20-25% cases)
Hyperdiploidy (>50 chromosomes/cell) (25% cases) associated with non-random trisomies X, 4, 6, 10, 14, 17, 18 and 21. Trisomy 4 and 10 alone (and in the past with trisomy 17 or "triple trisomy”) has been found to confer benefit. It is very important to confirm that "hyperdiploidy" does not represent doubling of a near-haploid clone, which has a poor prognosis
Other, less common, chromosomal abnormalities confer a poor outcome:
Extreme hypodiploidy with < 44 chromosomes/cell (1% of cases) which can be subdivided into near-haploid ALL (24–31 chromosomes) harboring mutations affecting receptor tyrosine kinase and RAS signaling, and low-hypodiploid ALL (32–39 chromosomes) characterized by alterations in TP53 as a manifestation of Li-Fraumeni Syndrome.
MLL gene rearrangement eg t(4;11)(q21;q23) (6% cases)
Philadelphia chromosome positivity t(9;22)(q34;q11) (3% cases)
Internal amplification of chromosome 21 (iAMP 21) (2% cases)
And some chromosomal abnormalities are of uncertain significance:
t(1;19)(q23;p13) or TCF3-PBX1 (formerly known as E2A-PBX1) (4% cases) was thought to confer poor prognosis with increased risk of CNS relapse, but this is no longer true with contemporary treatment.
Genome-wide association studies (GWAS) use techniques that are not widely available to define genetic abnormalities in the 20% of B-lineage ALL cases where routine testing is unrevealing, demonstrating changes associated with poor outcome:
"Ph-like" ALL (10-15% of cases) with gene expression similar to Ph+ ALL which commonly have IZKF1 alteration, and in half of cases cryptic rearrangements of CRLF2 (cytokine receptor like factor 2). Approximately half of CRLF2 -rearranged cases have point mutations in Janus kinase (JAK) family members JAK1 and JAK2
Increased CRLF2 (cytokine receptor like factor 2) expression, which may have an underlying CRLF2 mutation (5-7% of cases). Interestingly, increased CRLF2 expression is also seen in 50% of the patients with Down syndrome and ALL, where its prognostic value is uncertain.
T-lineage ALL also has a variety of chromosomal abnormalities with less well-defined prognostic value:
Constitutive activation of NOTCH1 signaling is the most common abnormality and secondary to activating mutations in NOTCH1 (>50% of cases of T-ALL), FBXW7 mutations (15% of cases), and t(7;9)(q34;q34.3) (< 1% of cases), and may convey favorable outcome.
Genetic lesions also include homeobox ( HOX), LMO, and bHLH family members. Amongst the HOX genes TLX1 rearrangement t(10;14)(q24;q11) was thought to confer a favorable prognosis (5-10% cases) and TLX3 rearrangement t(5;14)(q35;q32) less favorable (20-25% cases).
Minimal Residual Disease Studies
Traditionally, the response to leukemia treatment has been assessed morphologically, which can be challenging when looking for small numbers of leukemic cells, especially in bone marrow specimens recovering from chemotherapy or after transplantation.
Studies of minimal residual disease (MRD) may be based on the detection of chimeric transcripts generated by fusion genes, the detection of clonal TCR or immunoglobulin heavy-chain (IgH) gene rearrangements, or the identification of a immunophenotype specific to the leukemic blasts. All of the methods for detecting MRD have a much higher sensitivity than that of morphology, and all studies using MRD techniques have shown significant correlations between end-of-induction leukemia burden and outcome. As a result, current treatment protocols use MRD measurements for acute lymphoblastic leukemia risk assignment.
For B-lineage ALL patients, MRD is used as follows:
On COG P9904/5/6 clinical trials, multivariate analysis found Day 29 (end of induction)bone marrow (BM) MRD measured by flow cytometry with a cut-off of 0.01% was the most significant predictor of outcome in patients with B-ALL. The effect of MRD was quantitatively different among genetic subgroups and NCI risk groups. These studies also found that Day 8 peripheral blood MRD level was an independent predictor of outcome in multivariate analysis.
The UK ALL 2003 clinical trial also confirmed MRD as the single most important predictor of relapse, and patients with day 29 BM MRD ≥ 0.01% had a threefold higher relapse rate (5-year EFS 79%) compared with low-risk patients (5-year EFS 94-95%).
For T-lineage ALL patients:
The Italian Association of Pediatric Haematology-Oncology (AIEOP)-Berlin-Frankfurt-Muenster (BFM) 2000 study used PCR to measure MRD on Day 33 (end induction) and Day 78 (end of consolidation, EOC) and found EOC MRD a better predictor of adverse outcome in T-lineage ALL. Regardless of Day 33 MRD, patients who had EOC MRD < .01% had a 7-year EFS of at least 80%, in contrast to patients with EOC MRD >.01% who had a7-year EFS of 49%.
Perform testicular ultrasonography if the testes are enlarged upon physical examination.
Some clinicians use renal ultrasonography to evaluate for leukemic kidney involvement as an assessment of risk for tumor lysis syndrome.
Bone Marrow Aspiration and Biopsy
Bone marrow aspirate and biopsy results confirm the diagnosis of acute lymphoblastic leukemia (ALL). In addition, special stains (immunohistochemistry), immunophenotyping, cytogenetic analysis, and molecular analysis help in classifying each case. See the images below for examples of bone marrow aspirate findings.
According to the French-American-British (FAB) classification system, acute lymphoblastic leukemia (ALL) is classified into 3 groups based on morphology, as follows:
L1: The lymphoblast cells are usually small, with scant cytoplasm and inconspicuous nucleoli. L1 accounts for 85% of all cases of childhood acute lymphoblastic leukemia.
L2: The lymphoblast cells are larger than in L1. The cells demonstrate considerable heterogeneity in size, with prominent nucleoli, and abundant cytoplasm. L2 accounts for 14% of all childhood acute lymphoblastic leukemia.
L3: The lymphoblast cells are large and notable for their deep cytoplasmic basophilia. They frequently have prominent cytoplasmic vacuolation and are morphologically identical to Burkitt lymphoma cells. L3 accounts for 1% of childhood acute lymphoblastic leukemia cases.
Although the FAB system was used in the past, it is no longer useful (except for L3), because current standard diagnosis is based on immunophenotype and molecular techniques.
See Acute Lymphoblastic Leukemia Staging for more complete information.
Hackethal V. TKIs May Be New Treatment Option for ALL Subtype. Medscape Medical News. Available at http://www.medscape.com/viewarticle/831525. Accessed: Sep 24 2014.
Roberts KG, Li Y, Payne-Turner D, Harvey RC, Yang YL, Pei D, et al. Targetable kinase-activating lesions in Ph-like acute lymphoblastic leukemia. N Engl J Med. 2014 Sep 11. 371(11):1005-15. [Medline]. [Full Text].
Pui CH, Robison LL, Look AT. Acute lymphoblastic leukaemia. Lancet. 2008 Mar 22. 371(9617):1030-43. [Medline].
Ribera JM, Oriol A. Acute lymphoblastic leukemia in adolescents and young adults. Hematol Oncol Clin North Am. 2009 Oct. 23(5):1033-42, vi. [Medline].
Margolin JF, Steuber CP, Poplack DG. Acute lymphoblastic leukemia. Pizzo PA Poplack DG, eds. Principles and Practice of Pediatric Oncology. 15th ed. 2006. 538-90.
Hunger SP, Lu X, Devidas M, Camitta BM, Gaynon PS, Winick NJ, et al. Improved survival for children and adolescents with acute lymphoblastic leukemia between 1990 and 2005: a report from the children's oncology group. J Clin Oncol. 2012 May 10. 30(14):1663-9. [Medline]. [Full Text].
Ribeiro KB, Buffler PA, Metayer C. Socioeconomic status and childhood acute lymphocytic leukemia incidence in São Paulo, Brazil. Int J Cancer. 2008 Oct 15. 123(8):1907-12. [Medline].
Pieters R, Schrappe M, De Lorenzo P, Hann I, De Rossi G, Felice M, et al. A treatment protocol for infants younger than 1 year with acute lymphoblastic leukaemia (Interfant-99): an observational study and a multicentre randomised trial. Lancet. 2007 Jul 21. 370(9583):240-50. [Medline].
Magrath I, Shanta V, Advani S, Adde M, Arya LS, Banavali S, et al. Treatment of acute lymphoblastic leukaemia in countries with limited resources; lessons from use of a single protocol in India over a twenty year period [corrected]. Eur J Cancer. 2005 Jul. 41(11):1570-83. [Medline].
Muwakkit S, Al-Aridi C, Samra A, Saab R, Mahfouz RA, Farra C, et al. Implementation of an intensive risk-stratified treatment protocol for children and adolescents with acute lymphoblastic leukemia in Lebanon. Am J Hematol. 2012 Jul. 87(7):678-83. [Medline].
Ganesan P, Thulkar S, Gupta R, Bakhshi S. Childhood aleukemic leukemia with hypercalcemia and bone lesions mimicking metabolic bone disease. J Pediatr Endocrinol Metab. 2009 May. 22(5):463-7. [Medline].
de Labarthe A, Rousselot P, Huguet-Rigal F, Delabesse E, Witz F, Maury S, et al. Imatinib combined with induction or consolidation chemotherapy in patients with de novo Philadelphia chromosome-positive acute lymphoblastic leukemia: results of the GRAAPH-2003 study. Blood. 2007 Feb 15. 109(4):1408-13. [Medline].
Dubansky AS, Boyett JM, Falletta J, Mahoney DH, Land VJ, Pullen J, et al. Isolated thrombocytopenia in children with acute lymphoblastic leukemia: a rare event in a Pediatric Oncology Group Study. Pediatrics. 1989 Dec. 84(6):1068-71. [Medline].
Gaynon PS. Childhood acute lymphoblastic leukaemia and relapse. Br J Haematol. 2005 Dec. 131(5):579-87. [Medline].
Kawedia JD, Kaste SC, Pei D, Panetta JC, Cai X, Cheng C, et al. Pharmacokinetic, pharmacodynamic, and pharmacogenetic determinants of osteonecrosis in children with acute lymphoblastic leukemia. Blood. 2011 Feb 24. 117(8):2340-7; quiz 2556. [Medline]. [Full Text].
te Loo DM, Kamps WA, van der Does-van den Berg A, van Wering ER, de Graaf SS. Prognostic significance of blasts in the cerebrospinal fluid without pleiocytosis or a traumatic lumbar puncture in children with acute lymphoblastic leukemia: experience of the Dutch Childhood Oncology Group. J Clin Oncol. 2006 May 20. 24(15):2332-6. [Medline].
FDA approves Gleevec for children with acute lymphoblastic leukemia [press release]. US Food and Drug Administration. Available at http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm336868.htm. Accessed: February 1, 2013.
Lee S, Kim YJ, Min CK, Kim HJ, Eom KS, Kim DW, et al. The effect of first-line imatinib interim therapy on the outcome of allogeneic stem cell transplantation in adults with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia. Blood. 2005 May 1. 105(9):3449-57. [Medline].
Pulsipher MA, Peters C, Pui CH. High-risk pediatric acute lymphoblastic leukemia: to transplant or not to transplant?. Biol Blood Marrow Transplant. 2011 Jan. 17(1 Suppl):S137-48. [Medline]. [Full Text].
Schultz KR, Bowman WP, Aledo A, Slayton WB, Sather H, Devidas M, et al. Improved early event-free survival with imatinib in Philadelphia chromosome-positive acute lymphoblastic leukemia: a children's oncology group study. J Clin Oncol. 2009 Nov 1. 27(31):5175-81. [Medline]. [Full Text].
Schrappe M, Hunger SP, Pui CH, Saha V, Gaynon PS, Baruchel A, et al. Outcomes after induction failure in childhood acute lymphoblastic leukemia. N Engl J Med. 2012 Apr 12. 366(15):1371-81. [Medline]. [Full Text].
Buitenkamp TD, Izraeli S, Zimmermann M, Forestier E, Heerema NA, van den Heuvel-Eibrink MM, et al. Acute lymphoblastic leukemia in children with Down syndrome: a retrospective analysis from the Ponte di Legno study group. Blood. 2014 Jan 2. 123(1):70-7. [Medline]. [Full Text].
Bhojwani D, Pui CH. Relapsed childhood acute lymphoblastic leukaemia. Lancet Oncol. 2013 May. 14(6):e205-17. [Medline].
Mullighan CG, Phillips LA, Su X, Ma J, Miller CB, Shurtleff SA, et al. Genomic analysis of the clonal origins of relapsed acute lymphoblastic leukemia. Science. 2008 Nov 28. 322(5906):1377-80. [Medline]. [Full Text].
Parker C, Waters R, Leighton C, Hancock J, Sutton R, Moorman AV, et al. Effect of mitoxantrone on outcome of children with first relapse of acute lymphoblastic leukaemia (ALL R3): an open-label randomised trial. Lancet. 2010 Dec 11. 376(9757):2009-17. [Medline]. [Full Text].
Campana D, Leung W. Clinical significance of minimal residual disease in patients with acute leukaemia undergoing haematopoietic stem cell transplantation. Br J Haematol. 2013 Jul. 162(2):147-61. [Medline].
Eapen M, Raetz E, Zhang MJ, et al. a collaborative study of the Children's Oncology Group and the Center for International Blood and Marrow Transplant Research. Blood. Jun 15. 107(12):4961-7.
Cheok MH, Evans WE. Acute lymphoblastic leukaemia: a model for the pharmacogenomics of cancer therapy. Nat Rev Cancer. 2006 Feb. 6(2):117-29. [Medline].
Jones LK, Saha V. Philadelphia positive acute lymphoblastic leukaemia of childhood. Br J Haematol. 2005 Aug. 130(4):489-500. [Medline].
Brentjens RJ, Curran KJ. Novel cellular therapies for leukemia: CAR-modified T cells targeted to the CD19 antigen. Hematology Am Soc Hematol Educ Program. 2012. 2012:143-51. [Medline].
Mullighan CG, Su X, Zhang J, Radtke I, Phillips LA, Miller CB, et al. Deletion of IKZF1 and prognosis in acute lymphoblastic leukemia. N Engl J Med. 2009 Jan 29. 360(5):470-80. [Medline]. [Full Text].
Mullighan CG, Zhang J, Harvey RC, Collins-Underwood JR, Schulman BA, Phillips LA, et al. JAK mutations in high-risk childhood acute lymphoblastic leukemia. Proc Natl Acad Sci U S A. 2009 Jun 9. 106(23):9414-8. [Medline]. [Full Text].
Fuster JL, Bermúdez M, Galera A, Llinares ME, Calle D, Ortuño FJ. Imatinib mesylate in combination with chemotherapy in four children with de novo and advanced stage Philadelphia chromosome-positive acute lymphoblastic leukemia. Haematologica. 2007 Dec. 92(12):1723-4. [Medline].
Boggs W. Neurologic Changes Occur Long After Pediatric Lymphoid Malignancy. Medscape Medical News. Available at http://www.medscape.com/viewarticle/810241. Accessed: September 11, 2013.
Gordijn MS, Gemke RJ, van Dalen EC, Rotteveel J, Kaspers GJ. Hypothalamic-pituitary-adrenal (HPA) axis suppression after treatment with glucocorticoid therapy for childhood acute lymphoblastic leukaemia. Cochrane Database Syst Rev. 2012 May 16. 5:CD008727. [Medline].
Henze G, v Stackelberg A, Eckert C. ALL-REZ BFM--the consecutive trials for children with relapsed acute lymphoblastic leukemia. Klin Padiatr. 2013 May. 225 Suppl 1:S73-8. [Medline].
Hijiya N, Barry E, Arceci RJ. Clofarabine in pediatric acute leukemia: current findings and issues. Pediatr Blood Cancer. 2012 Sep. 59(3):417-22. [Medline].
Hill FG, Richards S, Gibson B, Hann I, Lilleyman J, Kinsey S, et al. Successful treatment without cranial radiotherapy of children receiving intensified chemotherapy for acute lymphoblastic leukaemia: results of the risk-stratified randomized central nervous system treatment trial MRC UKALL XI (ISRC TN 16757172). Br J Haematol. 2004 Jan. 124(1):33-46. [Medline].
Hong D, Gupta R, Ancliff P, Atzberger A, Brown J, Soneji S, et al. Initiating and cancer-propagating cells in TEL-AML1-associated childhood leukemia. Science. 2008 Jan 18. 319(5861):336-9. [Medline].
Landier W, Bhatia S, Eshelman DA, Forte KJ, Sweeney T, Hester AL, et al. Development of risk-based guidelines for pediatric cancer survivors: the Children's Oncology Group Long-Term Follow-Up Guidelines from the Children's Oncology Group Late Effects Committee and Nursing Discipline. J Clin Oncol. 2004 Dec 15. 22(24):4979-90. [Medline].
le Viseur C, Hotfilder M, Bomken S, Wilson K, Röttgers S, Schrauder A, et al. In childhood acute lymphoblastic leukemia, blasts at different stages of immunophenotypic maturation have stem cell properties. Cancer Cell. 2008 Jul 8. 14(1):47-58. [Medline]. [Full Text].
Mulcahy N. FDA Approves Imatinib for Pediatric ALL. Medscape Medical News. January 25, 2013. Medscape Medical News. Available at http://www.medscape.com/viewarticle/778062. Accessed: February 1, 2013.
Nathan PC, Wasilewski-Masker K, Janzen LA. Long-term outcomes in survivors of childhood acute lymphoblastic leukemia. Hematol Oncol Clin North Am. 2009 Oct. 23(5):1065-82, vi-vii. [Medline].
Pui CH, Campana D, Pei D, Bowman WP, Sandlund JT, Kaste SC, et al. Treating childhood acute lymphoblastic leukemia without cranial irradiation. N Engl J Med. 2009 Jun 25. 360(26):2730-41. [Medline]. [Full Text].
Schuitema I, Deprez S, Van Hecke W, Daams M, Uyttebroeck A, Sunaert S, et al. Accelerated aging, decreased white matter integrity, and associated neuropsychological dysfunction 25 years after pediatric lymphoid malignancies. J Clin Oncol. 2013 Sep 20. 31(27):3378-88. [Medline].
Schultz KR, Pullen DJ, Sather HN, Shuster JJ, Devidas M, Borowitz MJ, et al. Risk- and response-based classification of childhood B-precursor acute lymphoblastic leukemia: a combined analysis of prognostic markers from the Pediatric Oncology Group (POG) and Children's Cancer Group (CCG). Blood. 2007 Feb 1. 109(3):926-35. [Medline]. [Full Text].
Teachey DT, Hunger SP. Predicting relapse risk in childhood acute lymphoblastic leukaemia. Br J Haematol. 2013 Sep. 162(5):606-20. [Medline].
Thomas DA, Faderl S, Cortes J, O'Brien S, Giles FJ, Kornblau SM, et al. Treatment of Philadelphia chromosome-positive acute lymphocytic leukemia with hyper-CVAD and imatinib mesylate. Blood. 2004 Jun 15. 103(12):4396-407. [Medline].
Blincyto (blinatumomab) [package insert]. Thousand Oaks, CA: Amgen Inc. December 2014. Available at [Full Text].
Schlegel P, Lang P, Zugmaier G, Ebinger M, Kreyenberg H, Witte KE, et al. Pediatric posttransplant relapsed/refractory B-precursor acute lymphoblastic leukemia shows durable remission by therapy with the T-cell engaging bispecific antibody blinatumomab. Haematologica. 2014 Jul. 99(7):1212-9. [Medline]. [Full Text].