Leukemia in Children – Pediatrics | Lecturio

in this lecture we will review leukemia and children so leukemia is the malignant transformation and proliferation of Hamato poetic cells so we have acute leukemia which is a clonal expansion of immature precursors and we have chronic leukemia which is mature bone marrow components that are then becoming clone so symptoms can occur from a lack of normal bone marrow cell production or from accumulation of malignant cells in tissues that otherwise shouldn't have them so let's go through the epidemiology of leukemia and children it is the most common pediatric malignancy 30% of all newly diagnosed children with cancer have leukemia and Bowie is typically get it a little bit more than girls so we break down leukemia typically in kids into four major types by far and away the most common types are the first two let's go through these first we have acute lymphoblastic leukemia acute lymphoblastic leukemia or al L is very common in kids it's a proliferation of B and T cell lymphocyte precursors like you can see here it typically happens in children between the age of two and five and again boys a little more commonly than girls Caucasians are at greatest risk for a ll comparing that to AML which is acute myelogenous leukemia AM L is a cloner clonal proliferation of myeloid precursors so there are many subtypes of AML based on the morphology of the cells that are growing and the saito genic translocations that have occurred which caused these cells to become clonal in nature there's a generally bimodal incidence in terms of when children get this disease there's one peak in little tiny kids under 2 years of age and then again in adolescence this for AML unlike a ll the rate in boys and girls is about the same and this is associated with some toxic exposures also some genetic predispositions for example children with Down syndrome have a 50 fold increase in their risk for AML remember that Down syndrome and AML strong association now we would switch gears to chronic disease and this is chronic myelogenous leukemia which is less common in kids this is an uncontrolled growth of myeloid cells and the incidence increases through childhood and adolescence often these patients have a fusion protein the BCR Abel gene this constituents tyrosine kinase the mutation in this translocation between chromosome 9 and chromosome 22 causes a continuously on activation of tyrosine kinase and lastly we'll talk very briefly about the very mild form of leukemia which is juvenile Milo monocytic leukemia or JMML JMML is very rare it's usually diagnosed before the age of three and the etiology is basically unknown it is associated however with a few genetic conditions like Down syndrome neurofibromatosis li-fraumeni syndrome and Fanconi anemia so let's back off now and talk about what are the general symptoms of leukemia if a child it has leukemia what do they look like well first of all they're often lethargic they have less energy to get through their day sometimes they have respiratory distress if there's a mediastinal mass that might be pressing on the trachea or something but usually it's a nonspecific kind of lethargy some fatigue they may have increased bleeding if their platelet counts are down and they may have increased rates of infections children may present with bone pain as their chief complaint when they have leukemia also you may find on exam that they have fever power from an anemia tachycardia from an anemia and bruising in petechiae from low platelet counts they may have lymph adenopathy hepatosplenomegaly or in boys testicular enlargement from some tissues growing with cancer cells in them specifically the lymph and the splenic system they may have facial swelling and wheezing and tachypnea if they happen to have a mediastinal mass and they may have CNS involvement which actually is not uncommon in áall so how do we diagnose this problem well the first mainstay of picking up anemia is the CBC and frequently we will find signs on the CBC that something isn't right we usually will see what we say is two cell lines down sometimes one cell line down but often that could be something else for example if a patient has thrombocytopenia only this could be immune thrombocytopenic purpura not cancer we would treat that very differently but typically they'll have more than one cell line down which means they may have some anemia some thrombocytopenia some leukopenia some leukocytosis at times with a very high white count or neutropenia you also may see a particular type of cell called a blast when you say a blast on a CBC differential you are should be highly concerned that that patient might have cancer and you should probably refer that patient to a hematology oncologist in CML we sometimes see very marked hyper leukocytosis with white counts in the fifty to a hundred range and we often see normal my load precursors on those CBC's also in patients where we suspect they might have leukemia we often will check a chemistry panel to look for signs of tumor lysis syndromes such as a high potassium or high phosphate so we we'll check that but that's not a great diagnosis mechanism though rarely you may see it also we could do if the patient specifically had CML we could look for the bcr-abl gene that's usually a little bit later on what radiology do we get we usually get a chest x-ray and a chest x-ray can often show a large mediastinal mass like you can see in this patient with a widened mediastinum to confirm the diagnosis we will do a bone marrow aspiration and a biopsy to try and get some of that bone marrow tissue that is then sent for cytology and you can actually identify the type of cancer off of cytology additionally we will often do a lumbar puncture to inspect for CNS involvement especially in a ll so who is it highest risk when they have leukemia who are the high risk patients well children more than ten years and less than one year are at higher risk the children between one and ten are at lower risk if their white count is very very high they're at higher risk if they have a T cell phenotype they're at higher risk and if they have cytogenetic changes in their leukemia cells they're at higher risk and lastly make sense if they're not responding well to therapy they're at higher risk so what is the therapy we're giving well it depends on the type of cancer obviously in fact there are complicated pathways and roadmaps that are established by multi Center groups that are how we treat these children in a very standardized way so what you'll see is if you're taking care one of these patients they'll have a road map that'll say things like for example on day seven they have to get intrathecal methotrexate on day 14 they'll get something else it's a very prescribed pathway we try very hard to follow the road map because it's been shown to have improved outcomes so what is that road map involve well an al L this is going to be a multi agent chemotherapy with multiple agents generally for two to three and a half years and also they will get some prophylactic intrathecal chemotherapy and/or radiation to sanctuary sites for AML we will do multi agent intensive chemotherapy for six to nine months but some of these patients will weren't getting a Hamada poetic stem cell transplant for CML we're going to give single agent therapy with tyrosine kinase inhibitors for the BCR Abel gene and a hematopoietic stem cell transplant for a poor response and for JMML these patients awfully require a bone-marrow transplant so what's the prognosis for these patients surprisingly good for al more than eighty percent and even as high as ninety five percent of patients and low-risk groups are going to survive they're al l this is a great accomplishment we have in pediatrics for AML it really depends on the subtype of animal but it's probably around fifty percent survival rate for CML this is a lifelong disorder with tyrosine kinase inhibitor therapy and for JMML about survival of about forty percent unfortunately with a bone marrow transplant which requires all the complications of bone marrow transplants but in general most children have al and most children have a pretty good prognosis it being cancer so that's my review of leukemia in children thanks for your time


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