The initial presentation of patients with AML may vary from the discovery of relatively asymptomatic cytopenias at the time of routine health maintenance exams to life-threatening complications, requiring urgent intervention. Signs and symptoms of AML mostly reflect the effect of cytopenias. Patients typically present with a short history (few weeks to 3 months) of constitutional symptoms (fatigue, lack of energy, malaise, fever, profuse sweats), infections, and/or manifestations of bleeding (e.g., gingival bleeding, bruising, epistaxis, menorrhagia). Fevers should always be presumed to be secondary to infections even in the absence of an identifiable focus and lead to rapid institution of antibiotic therapy. “Tumor fever” due to AML does occur but remains a diagnosis of exclusion. Extramedullary leukemic infiltrates in the gingiva, skin, lymph nodes, or other organs occur occasionally, and are more often associated with monocytic differentiation. Signs and symptoms referable to central nervous system (CNS) involvement (cranial neuropathies and other focal neurologic abnormalities, encephalopathy, seizures) are rare, except for AML with monocytic/monoblastic differentiation or in any AML with considerable leukocytosis (> 100,000/ μ L). The life-threatening complications requiring emergent intervention include clinical leukostasis, spontaneous tumor lysis syndrome (TLS) with renal failure, and DIC with hemorrhagic or occasionally thrombotic complications (see Initial Therapy).
Findings after physical examination are often nonspecific. Patients may demonstrate pallor, tachycardia, oral purpura, ecchymoses, and petechiae due to anemia and thrombocytopenia. There may be signs of extramedullary leukemia such as gingival hypertrophy, enlargement of lymph nodes, cutaneous nodules (leukemia cutis), or hepatosplenomegaly. Examination of the lungs may reveal signs of an infectious process. Many patients with AML have no abnormal findings on physical examination at presentation.
The laboratory evaluation should include blood counts with eval uation of the blood smear, a standard chemistry panel (electrolytes, urea nitrogen, creatinine, total bilirubin, transaminases, uric acid, lactate dehydrogenase [LDH]), and coagulation studies, including prothrombin time (PT), partial thromboplastin time (PTT), and fibrinogen levels. Anemia and thrombocytopenia are almost always present. The white blood cell (WBC) count can vary from low to extremely high ( > 100,000/ μL). Spurious hypoxia and hypoglycemia may occur in the setting of hyperleukocytosis due to continued metabolism by the leukemic blasts prior to processing of a blood sample for analysis; spurious hyperkalemia can occur in the setting of hyperleukocytosis due to cell lysis during clot formation in the preparation of serum. On the other hand, hypokalemia is not infrequently observed with monoblastic AML. DIC may be present at diagnosis and is often seen in patients with monocytic AML and APL. Subclinical DIC, evident by elevated D-dimers, is common in many forms of AML and can worsen with the institution of therapy. Abnormalities of renal and hepatic values may represent infiltration of these organs; renal dysfunction is commonly observed at presentation due to spontaneous TLS or hypoperfusion due to capillary leak syndrome.
Imaging studies are of little help in diagnosis but allow assessment of complications (pneumonia, cerebral hemorrhage). If patients present with any neurologic deficit, the threshold for computed tomography (CT) scan (non-contrast if bleeding is of concern) or any other imaging modality of the brain should be low. Further evaluations should be based on the clinical assessment of the patients.
