Leukemia Notes PDF

(L6) LEUKEMIA  LECTURE 06 LEUKEMIA OVERVIEW DEFINITION  It is a malignant disease of blood cells that can affect WBCs, RBCs & PLT (Mainly WBCs)  It is the most common malignant disease...

(L6) LEUKEMIA  LECTURE 06 LEUKEMIA OVERVIEW DEFINITION  It is a malignant disease of blood cells that can affect WBCs, RBCs & PLT (Mainly WBCs)  It is the most common malignant disease in children. Types ① ALL → 75% ② AML → 15-20% ③ CML, AUL, AMLL → 5%  No CLL in pediatrics  ALL is the most common type of leukemia in children ETIOLOGY  Multifactorial  Predisposing factors: ① Chemical ② Irradiation ③ Pollution ④ Genetic disorders (e.g. Down syndrome) ⑤ Viral infection PATHOGENESIS  Stop of maturation of blast cells → ↑ number of blast cells upon the other types of cells in B.M. Dr.Noaman Page 1  Medicine - Delta Semester (7) Leukemia CLINICAL PICTURE ① ↓ RBCs → Pallor ② ↓ PLT → Purpura ③ ↓ WBCs → Fever  The 3 manifestations are not always present together.  So, if the patient complains from unexplained fever only or anemia or purpura → leukemia must be considered in the D.D. ④ Generalized lymphadenopathy ⑨ Testicular infiltration ⑤ Splenomegaly ⑩ Tender bone ⑥ Hepatomegaly ⑪ Arthralgia or Arthritis ⑦ CNS leukemia ⑫ Fever with unknown origin ⑧ Facial palsy ⑬ Weight loss INVESTIGATIONS 1 For diagnosis of leukemia  CBC & Blood film: ① Anemia ② Thrombocytopenia ③ WBCs:  Leukocytosis (the most common)  Leucopenia ④ Blast cells may be present Notes  If WBCs > 50.000 = Unfavorable Prognosis  Hyperleukocytosis → W.B.C.s count > 100.000 Dr.Noaman Page 2  Medicine - Delta Semester (7) Leukemia 2 For type of leukemia ① By cytochemical studies ② By use of different stains:  Lymphoblast  Myeloblast 1. P.A.S. 1. Sudan black 2. Acid phosphatase 2. Peroxidase Dr.Noaman Page 3  Medicine - Delta Semester (7) Leukemia 3 For subtype of leukemia  By FAB classification (French - American - British) according to morphological background ALL  Small L1  Mild basophilia of cytoplasm  Large cell L2  Variable basophilia of cytoplasm  Large cell L3  Deep basophilia of cytoplasm L1 L2 L3 AML M0  Undifferentiated cells M1  Myeloblastic without maturation M2  MyelobIastic with maturation M3  Pro-myelocytic leukemia M4  Myelo-monocytic leukemia M5  Monocytic leukemia M6  Erythrocytic leukemia M7  Megakaryoblastic leukemia  Other recent investigations for different subtypes of leukemia: Test Flowcytomertic tests Cancer cytogenetic  Differentiate between different  To detect certain specific Importance types based on surface antigens on translocation blasts  For ALL ① Pre B ALL blasts express ① t(12,21) is favorable Example (CD19, 22, 79a, 10) ② 11q23 is unfavorable ② T ALL (expresses CD2, 3, 5, 7) ③ t(9,22) is unfavorable Dr.Noaman Page 4  Medicine - Delta Semester (7) Leukemia 4 Other investigations ① CXR ⑤ Serum uric acid ② Abdominal U/S ⑥ Immunophenotyping ③ Liver function tests ⑦ Cytogenetic studies ④ Kidney function tests Bad prognostic criteria of ALL ① Age → < 1 years or > 10 years. ⑧ Testicular infiltration ② Sex → male ⑨ CNS infiltration ③ Race → black ⑩ T cell leukemia ④ WBCs > 50.000 /mm3 ⑪ Unfavorable cytogenetics ⑤ Severe thrombocytopenia ⑫ Incomplete remission after induction ⑥ Mediastinal L.N. enlargement chemotherapy ⑦ Huge HSM Risk group stratification  Risk group stratification according to Children Oncology Group (COG) ① Age 1 to