Acute myeloid leukaemia.
This is neoplastic proliferation of blast cells derived from myeloid elements within the bone marrow. It is among the most rapidly progressive malignancies.
Clinical features: marrow failure: anemia, infection, bleeding, DIC.
Leukaemic infiltration: bone pain, tender sternum, CNS signs like cord compression and cranial nerve lesions, gums, testis and orbit infiltration, hepatosplenomegaly, lymphadenopathy, skin and perianal involvement.
Constitutional features: malaise, weakness, fever, polyarthritis.
Diagnosis: WCC is variable. Diagnosis depends on bone marrow biopsy.
Complications: leucostasis may cause pulmonary and cerebral infarcts and death. To reduce the blast count quickly a single dose of daunorubicin or doxorubicin may be given with allopurinol to counter the high uric acid level. Emergency cranial radiotherapy may be given. Massive mediastinal lymphadenopathy may give rise to dyspnoea.
Treatment: supportive care: blood and platelet transfusion, barrier nursing, IV antibiotics.
Chemotherapy: is very intensive, resulting in long periods of neutropenia and thrombocytopenia. The main drugs used are daunorubicin and thioguanine.
Bone marrow transplant (BMT): allogenic transplant from histocompatible siblings or from unrelated donors syngenetic transplants from a twin may be indicated in the first or subsequent remissions. The idea is to destroy the leukaemic cells and the entire immune system by cyclophosphamide and total body irradiation, and repopulate the marrow by transplantation from a matched donor infused IVI. Cyclosporin ` methotrexate may be used to prevent graft versus host disease.
Prognosis: chemotherapy: 20%. BMT: perhaps 50%.