The leukemias are malignant neoplasms of the hematopoietic stem cells characterized by diffuse replacement of the bone marrow by neoplastic cells.In most cases,the leukemic cells spill over into the blood,where they may be seen in large numbers.These cells may also infiltrate the liver,spleen,lymph nodes,and other tissues throughout the body.Although the presence of excessive numbers of abnormal cells in the peripheral blood is the most dramatic manifestation of leukemia,it should be remembered that the leukemias are primary disorders of the bone marrow.Indeed,some patients with a diffusely infiltrated bone marrow may present with leukopenia rather than leukocytosis.
Traditionally,leukemias are classified on the basis of the cell type involved and the state of maturity of the leukemic cells.The acute leukemias are characterized by the presence of very immature cells(called blasts) and by rapidly fatal course in untreated patients-have the following CLINICAL FEATURES:
* abrupt stormy onset:most patients present within three months of the onset of symptoms
*symptoms related to depression of normal marrow function:fatigue due mainly to anemia;fever,reflecting an infection due to absence of mature leukocytes;bleeding(petechiae,ecchymoses... bleeding) secondary to thrombocytopenia
*bone pain and tenderness,resulting from marrow expansion with infiltration of the subperiosteum
*generalized lymphadenopathy,splenomegaly, and hepatomegaly,reflecting dissemination of the leukemic cells;this occurs in all acute leukemias,but more commonly in ALL(acute lymphocytic leukemia)
*central nervous system manifestations such as headache,vomiting, and nerve palsies resulting from meningeal spread;these features are more common in children than in adults, and more common in ALL than in AML(acute myeloblastic leukemia)
LABORATORY FINDINGS:Anemia is almost present.The white blood cell count in variably elevated,sometimes to more than 100,000 cells per microliter,but in about 50% of the patients is less than 10,000 cells per microliter.Much more important is the identification of immature white cells,including blast forms,in the circulating blood and the bone marrow,where they make up 60 to 100% of all the cells.The platelet count is usually depressed to less than 100,000 per microliter.Uncommonly,there is pancytopenia with few blast cells in the blood(aleukemic leukemia), but the bone marrow is nonetheless flooded with blasts,ruling out ablastic anemia.
--------on the other hand a lymphoma can appears with similar clinical features.Because of the family history,only the laboratory findings,maybe a biopsy of the lymph node or/and the bone marrow can establish the diagnosis.But i can tell you that a simple lymphadenitis maybe occurs.She must check it because of the family history of leukemia.