Case Study #7 MICR 410 – Hematology Spring 2010 Erik Bayona, Rosa E. Loyola, Lien Pham

Case Summary John, a 4-year-old male is seen by his physician with a complaint of easy fatigue and bruising. His mother states that until one month ago he was a “typical kid”. Since then she has noticed increased lassitude, a regression to more baby-like behavior, and loss of appetite. For the past two days his temperature has been 100ºF. Upon physical examination the child presented as a pale, quiet child of appropriate size for his age. Most systems were unremarkable with the exception of several small shotty lymph nodes felt in the cervical and auxiliary regions. His CBC revealed a WBC count of 40.2 x 10 ⁹ /L with 90% blasts. CBC Results:Hgb9.7 g/dL Hct32% RBC3.45 x10¹²/L WBC40.2 x 10 ⁹ /L Platlets63 x 10 ⁹ /L MCV92.7 fl MCH28.1 pg MCHC 30.3 Differential: 90% lymphoblasts 8% neutrophils 1% monocytes 1% eosinophils Rare nucleated RBCs Platelets appeared decreased in number

Key Information Pointing to Diagnosis Key Information Pointing to Diagnosis Age – 4 year old male w/ immature cells (90% blasts) Age – 4 year old male w/ immature cells (90% blasts) Sudden onset Sudden onset Lack of promyelocytes and lack of Auer rods Lack of promyelocytes and lack of Auer rods normocytic, normochromic anemia, low platelets, and high WBC normocytic, normochromic anemia, low platelets, and high WBC fatigue, bruising, paleness fatigue, bruising, paleness swollen lymph nodes swollen lymph nodes

The Diagnosis for Case #7 Precursor B cell Acute Lymphocytic Leukemia (ALL) type L1

Pathophysiology of Pre B ALL-L1 Precursor B ALL-L1 is characterized by a malignant transformation of B cells of the lymphoid cell line. This leads to an unregulated proliferation of immature B lymphocytes due to the arrest in maturation at the blast stage. The poorly differentiated malignant lymphocytes proliferate, accumulate, and invade normal tissues and cause lesions. The leukemic cells may replace normal cells, take over normal parts of the bone marrow, and cause bone marrow failure. This disrupts normal hematopoiesis and may result in pancytopenia with death from hemorrhaging and infections. The exact cause is unknown but there are certain predisposing factors : ◦Inherited increased predisposition to develop leukemia ◦Inherited tendency for chromosome fragility or abnormality (chromosomal translocations) ◦Those with hereditary immunodeficiencies ◦Those with chronic marrow dysfunction ◦Exposure to radiation, mutagenic chemicals or drugs ◦Viral infections

Bone Marrow Biopsy - usually needed to establish a definitive diagnosis of leukemia because cell morphology must be examined and bone marrow must be evaluated before calling it leukemia. Cytochemistry- will be helpful once the diagnosis of leukemia has been made, and can be used primarily to distinguish between ALL and AML. Will help establish the lineage of the leukemic cell as myeloid or lymphoid. Acid Phosphatase – T lymphocytes have a high level of acid phosphatase and this can be used to help make a diagnosis of acute T-lymphocytic leukemia. Cytogenetic studies – will be helpful for chromosome analysis to identify the specific malignancy and then provide a prognosis. Usually, a normal karyotype is usually associated with a better prognosis. Immunophenotyping - determining B cell or T cell lineage. These tests rely on antibodies made against specific surface markers. Flow cytometry – clinical mainstay for diagnosis pre-cursor B- cell ALL. Diagnostic Tests for Pre B ALL-L1

Therapy and Prognosis for Pre B ALL-L1 The prognosis is poor if the WBC count is > 20 x 10 /L However, an affected B-cell lineage shows a better therapeutic outcome A younger age is also better for recovery 70% of children diagnosed with ALL may be cured and have long term survival Therapy: Give supportive care – due to patient having bleeding issues, infection, anemia, etc. Eradicate leukemic cell masses using: 1.Chemotherapy – combination of drugs (primary treatment) 2.Radiotherapy – targets rapidly dividing cells therefore decreasing proliferation 3.Immunotherapy - stimulate patients’ own immune system to mount response against malignant cells 4.Monoclonal antibodies – antibodies that wipe out malignant cells 5.Bone marrow transplant – replacing bone marrow (used as last resort if all the above don’t work)

Prevention of Pre B ALL-L1 Most information about the cause of ALL comes from genetic studies – cytogenetics and epigenetics. Most information about the cause of ALL comes from genetic studies – cytogenetics and epigenetics. Chromosomal translocations – the most common for precursor B-cell ALL In children is the t(12;21) occuring in 16-28% of unselected cases. Results in fusion of TEL gene on chromosoe 12 and the AML1 gene on chromosome 21q. Chromosomal translocations – the most common for precursor B-cell ALL In children is the t(12;21) occuring in 16-28% of unselected cases. Results in fusion of TEL gene on chromosoe 12 and the AML1 gene on chromosome 21q. Epigenetic studies show aberrant methylation of DAPK gene and results suggest this may be of clincal-pathologcal significance for childhood ALL. Epigenetic studies show aberrant methylation of DAPK gene and results suggest this may be of clincal-pathologcal significance for childhood ALL. Prevention would focus on eliminating these probable causes – further research will provide answers and options. Prevention would focus on eliminating these probable causes – further research will provide answers and options.

Take Home Message The diagnosis is Precursor B cell Acute Lymphocytic Leukemia type L1. Typical symptoms are fatigue, pallor, fever, weight loss, irritability, anorexia, infection, bleeding, and bone pain. The cause of ALL L1 still largely speculative based on genetic research data. Diagnostic tests include acid phosphate,terminal deoxytidyl transferase, immunologic markers, and cytogenetics to identify chromosomal abnormalities. Treatment is to give supportive care and eradicate malignant cells using chemotherapy which is the primary and most useful treatment method. Prognosis is good due to age of the patient (child). Prevention will be further clarified with forthcoming research in genetics.

References 1. “FactSheet on ALL in children.” National Cancer Institute. July 11, May 23, McQueen, Nancy. “Introduction to Leukemia: Acute Leukemias.”Micro 410 – Hematology Lecture Notes, Spring Satake, Noriko. “Pediatric Acute Lymphoblastic Leukemia.” 4. MedEscape Reference: Drugs, Condition, and Procedures. 5. WebMd; May 2, Web. May 23, Seisho T; Masahide M; Zimmermann, M; Takayuki, I; Komatsu, N; Seriu, T; Schrappe, M; Bartram, C; Koeffler, H. Clinical significance of aberrant DNA methylation in childhood acute lymphoblastic leukemia, Leukemia Research, In Press, Corrected Proof, Available online 17 May 2011, ISSN , DOI: /j.leukres