11 جمادي الاخرة 1435 هـ Ped.Lec. by Dr.Shihaab
11/4/2014
LEUKEMIAS
Is the increase in the immature WBC either in the blood or in the bone marrow (BM).
The frequency is about 40 children per million/year.
Acute lymphoblastic leukemia (ALL) account 75% of leukemias, the various subtypes account 15-20%.
Chronic leukemias are quite rare in children.
Etiology:
there are few instances of familial leukemia. Children exposed to ionizing radiation or chemotherapy (especially topoisomerase inhibitors) are at increased risk.+ Diseases associated with increased risk for leukemia;
1-down syndrome
2- fanconi anenia
3- bloom syndrome
4- ataxia telangiectasia
5-turner syndrome
6- klienfilter syndrome
7- schwachman syndrome
8-neurfibromatosis
9- severe combined immune deficiency
10- paroxysmal nocturnal Hb urea
Clinical manifestations of ALL:
Some patients give history of preceding upper respiratory tract infection 1-2 months before the onset.
Signs and symptoms of acute leukemia are related to the infiltration of leukemic cells into the normal tissues, resulting either to bone marrow failure ( eg. Anemia, neutropenia , thrombocytopenia), or specific tissue infiltration ( eg. Lymph nodes, spleen, liver, bone, brain, skin , gingiva, and testes).
Common presenting symptoms are fever, pallor, and petchia or ecchymosis, lethargy ,malaise, anorexia, bone and joint pain.
Physical examination frequently reveals lymphadenopathy and hepatosplenomegally, and may be bone or joint swelling, symptomatic CNS involvement is rare at the time of presentation of acute leukemia.
In patient of acute myeloid leukemia, exramedullary soft tissue tumors may be found in various sites( eg, testes).
Management of ALL:
ALL is diagnosed by bone marrow aspiration, in which lymphoblasts is > 25% of the BM cells.The single most important prognostic factor of ALL is the treatment: without effective therapy the disease is fatal.
Induction 4-5 weaks by; vincristine, dexamethasone, L- asparagenase, and intrathecal cystone.
consolidation ; by intrathecal methotrexate and cranial radiotherapy
interim maintenance ; by daily oral 6-mercaptopurine, weakly oral methotrexate
maintenance; vincristine monthly, dexamethasone 5 days/ month, daily oral 6-mercaptopurine, and weakly oral methotrixate
Acute myelogenous leukemia (AML):
The clinical manifestation of AML, as in ALL, is due to replacement of bone marrow by malignant cells and to secondary bone marrow failure, in addition. AML may present with subcutaneous nodules, blueberry muffin lesions. Infiltration of the gingiva, signs and lab finding of DIC, and discrete masses known as chloromas or granulocytic sarcomas .Subtypes of AML
M1- AML without maturation
M2- AML with maturation
M3- ACUTE promyeloblastic leukemia
M4- acute myelomonocytic leukemia
M5- acute monocytic leukemia
M6- erythroleukemia
M7- acute megakaryocytic leukemia
Chronic myelogenous leukmia(CML):
CML is account of 2-3 of all cases of childhood leukemia. About 99% associated with a specific translocation t(9;22) (q 34; q11) known as Philadelphia chromosome .
The spleen often is greatly enlarged resulting in pain in the left upper quadrant of the abdomen.
The presenting symptoms of CML are entirely nonspecific as fever, fatigue, weight loss and anorexia.
Diagnosis is suggested by increase number of myeloid cells in blood and B.M, and confirmed by cytogenetic study that demonstrates the presence of Philadelphia chromosome.