Can AML Cause Gross Hematuria?
Yes, AML can cause gross hematuria, though it is a rare presenting feature that typically results from thrombocytopenia-related mucosal bleeding and possible occult leukemic infiltration of the urinary tract. 1, 2
Mechanism and Clinical Presentation
Hematuria in AML occurs through two primary mechanisms:
Thrombocytopenia-induced bleeding: AML typically presents with bone marrow failure leading to thrombocytopenia, which manifests as bleeding symptoms including petechiae, bruising, and mucosal bleeding. 1 While mucosal bleeding usually presents as gum bleeding or epistaxis, it can occur in any mucosal surface of the body, including the urinary tract. 2
Occult leukemic infiltration: Case reports document that gross hematuria can occur without demonstrable leukemic infiltration on imaging studies, suggesting microscopic infiltration of the urinary system that becomes clinically apparent when combined with thrombocytopenia. 2 The hematuria typically subsides after initiating chemotherapy, supporting this mechanism. 2
Coagulopathy Considerations
AML is frequently complicated by coagulation abnormalities that can exacerbate bleeding:
Disseminated intravascular coagulation (DIC) occurs in 8.5-25% of non-APL AML cases, with bleeding being a potential manifestation. 3 The prevalence of severe coagulation abnormalities in acute myeloid leukemia across all FAB types is approximately 12%. 4
Standard coagulation screening should be performed before any invasive procedures, including evaluation of prothrombin time, partial thromboplastin time, and fibrinogen activity. 5 This is particularly important given that coagulopathy is common at presentation in many leukemias. 5
Clinical Significance and Management
When hematuria is the presenting feature:
Maintain high clinical suspicion: While rare as an isolated or main presenting feature, hematuria should be remembered as a possible manifestation of acute leukemia. 2 The diagnosis requires comprehensive evaluation including complete blood count with differential and bone marrow examination. 5, 1
Immediate supportive care: Thrombocytopenia-related symptoms require platelet transfusion support, with thresholds of ≥50,000/μL if clinical coagulopathy or overt bleeding is present. 6 For non-APL AML with DIC, maintain fibrinogen >150 mg/dL with cryoprecipitate and fresh frozen plasma. 6
Definitive treatment: The hematuria typically resolves with initiation of appropriate chemotherapy for the underlying leukemia, as the cytoreduction addresses both the thrombocytopenia and any occult infiltration. 2
Important Caveats
The absence of demonstrable urinary tract infiltration on imaging does not exclude AML as the cause of hematuria when other hematologic abnormalities are present. 2 The combination of gross hematuria with cytopenias or other systemic symptoms warrants immediate hematologic evaluation rather than isolated urologic workup.