| Leukemia, cancer of the blood-forming tissues, is the | | | | subdivided according to another system known as |
| most common form of childhood cancer. However, | | | | the French-American-British (FAB) system. In the FAB |
| even for a child with the most favorable prognosis, | | | | system, the subtypes are determined after a |
| leukemia presents innumerable physical, clinic, | | | | thorough study of the morphology (structure) and |
| physicians' office, and community can do much to | | | | cytochemical reactivity of the leukemic cells. |
| prevent some problems and lessen others. | | | | Accordingly, ALL is subdivided into 3 types, Li stands |
| Classification | | | | for Lymphoblastic leukemia, child type, which |
| Leukemia is a broad term given to a group of | | | | accounts for 80% to 85% of all childhood leukemia |
| malignant diseases of the bone marrow and lymphatic | | | | and has the best prognosis, ANLL is classified into 7 |
| system. Current research has revealed that it is a | | | | types and comprises 10% to 20% of the leukemias |
| complex disease of varying heterogeneity. | | | | in children. The types with the best prognosis are Mi, |
| Consequently classification has become increasingly | | | | acute myelocytic leukemia without differentiation, and |
| more sophisticated and essential, since identification | | | | Mz, acute myelotic leukemia with differentiation. |
| of the subtype of leukemia has therapeutic and | | | | The various cells also demonstrate different reactions |
| prognostic implications. The following is an overview | | | | when they are exposed to certain chemicals. For |
| of the morphologic, cyto-chemical and immunologic | | | | example, lymphoblasts show no reactivity to Sudan |
| characteristics of the leukemia. | | | | black stain and perioxidase, whereas myeloblasts |
| Morphology and cytochemical markers | | | | demonstrate reactivity to both. |
| Leukemia is classified according to its predominant cell | | | | Another important differentiation between the cell |
| type and level of maturity. As described by the | | | | types is the absence or presence of Auer rods, |
| following: | | | | granules containing RNA that appear in the cytoplasm |
| Lympho- for leukemia involving the lymphoid or | | | | of affected myeloblasts and promyelocytes. Their |
| lymphatic system. | | | | presence is a strong diagnostic indicator for certain |
| Myelo- for those of myeloid (bone marrow) origin | | | | types of ANLL and is associated with improved |
| Blastic and acute- for those involving immature cells | | | | prognosis. |
| Cystic and chronic- for those involving mature cells | | | | The main clinical symptoms |
| In children, two forms are generally recognized: acute | | | | Fever, which the child shows during long time |
| lymphoid leukemia (ALL) and acute nonlymphoid | | | | and there is no evident signs of infection |
| (myelogenous) leukemia (ANLL or AML). Synonyms | | | | Pain in joints and bones (ossalgia) |
| for ALL include lymphatic, lumphocytic, lymphoblastic, | | | | Pale color of the skin |
| and lympho-blastoid leukemia. Usually the term "stem | | | | Enlargement of peripheral lymphatic nodes of |
| cell" or "blast cell leukemia" also refers to the | | | | different groups which are usually not painful; during |
| lymphoid type of leukemia. Synonyms for the ANLL | | | | palpation |
| type include granulocytic, myelo-cytic, monocytic | | | | Enlargement of liver and spleen |
| myelogenous, monoblastic, and mono-myeloblastic. | | | | Fatigue |
| There are also much rarer forms of leukemia that | | | | Hemorrhage syndrome petechiae, bruises and |
| are named for the specific cell involved, such as | | | | bleeding) |
| basophilic or eosinphilic leukemia. | | | | Laboratory diagnostic |
| Because of the confusion and inconsistency in | | | | Laboratory diagnostic includes common blood analysis. |
| classifyin the leukemias, acute lymphoblastic and | | | | WBC differential count and sternal puncture. |
| acute nonlymphoblastic leukemias are further | | | | |