Acute lymphoblastic leukemia in children: diagnosis
Acute lymphocytic leukemia accounts for up to 80% of leukemias in children. Most of the remaining nosologies include acute myeloid / acute non-lymphocytic leukemia (AML / ONLL). Chronic myeloid leukemia and other myeloproliferative disorders are rare.
The clinical picture of leukemia in children. Clinical signs and symptoms result from infiltration of the bone marrow or other organs with leukemic blast cells.
In most children, the onset of the disease goes without expressed complaints for several weeks with the following symptoms:
- pallor of the skin and mucous membranes;
- abnormal hematomas;
- enlarged lymph nodes;
- pain in the bones.
In some children, the disease progresses very quickly.
In most cases, but not in all children, a blood test is abnormal (low Hb and thrombocytopenia), as well as evidence of the spread of blast cells. A bone marrow examination is necessary to confirm the diagnosis and identify the immunological and cytogenetic characteristics that provide useful prognostic information.
Both acute lymphoblastic leukemia and AML are classified based on morphology. Immunological phenotyping further classifies ALL into subclasses. B-cell (75%) and T-cell (15%) subtypes are the most common subclasses.
The prognosis and some aspects of the clinical picture change with other subtypes, and accordingly treatment is selected for this. The prognosis of acute lymphoblastic leukemia depends on age, tumor load (determined by the number of leukocytes), the speed of response to the initial chemotherapy and the presence or absence of certain cytogenetic / molecular genetic abnormalities in the tumor cells.
High leukocyte counts (> 50×109 / l), under 1 year old or over 10 years of age with bone marrow blasts and submicroscopic leukemia levels (minimal residual disease) at the end of the first phase (induction) of treatment are important variables in determining the intensity of treatment.
Cytogenetic studies of the bone marrow in diagnosis are important for identifying certain prognostic factors that can lead to a correction in the intensity of therapy.