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Renal angiomyolipoma-patient characteristics and treatment with focus on active surveillance
Jesper Swärd1, Olof Henrikson2, David Lyrdal3
1Department of Urology, NU-Hospital Group, Uddevalla, Sweden.
Insights
Renal angiomyolipoma (AML) bleeding risk is low in sporadic cases during active surveillance (AS), but TSC-associated AML requires tailored follow-up due to higher intervention rates.
Area of Science:
- Urology
- Nephrology
- Oncology
Background:
- Renal angiomyolipoma (AML) is a benign kidney tumor.
- Active surveillance (AS) is a management option for renal AML.
- Tuberous sclerosis complex (TSC) is associated with a higher incidence of AML.
Purpose of the Study:
- To evaluate the bleeding risk of renal AML during AS.
- To compare bleeding risk between sporadic AML and TSC-associated AML.
- To inform management guidelines for renal AML.
Main Methods:
- Retrospective review of 98 patients with renal AML (1999-2014).
- Analysis of bleeding events, tumor size, and growth during AS.
- Comparison of outcomes in sporadic AML versus TSC-associated AML.
Main Results:
- 20% of AML patients presented with bleeding.
- Sporadic AML showed a low bleeding risk (1/45) during AS with a mean size of 34mm.
- TSC-associated AML had a higher bleeding risk and growth rate, necessitating intervention in all six patients.
Conclusions:
- Active surveillance is safe for sporadic renal AML <50mm.
- TSC-associated AML requires individualized follow-up due to increased bleeding and growth risks.
- Management strategies should differentiate between sporadic and TSC-associated AML.
Abstract:
Objectives: To present a patient material of renal angiomyolipoma (AML) with focus on the risk of bleeding during active surveillance (AS).Methods: Medical records, 1999-2014, were studied and 98 patients (80 female, 18 men) with renal AML were identified. Eleven patients had tuberous sclerosis complex (TSC). Mean age was 54 (13-89) years.Results: Sixty patients (61%) were asymptomatic at presentation, 33 (34%) presented with flank pain and five (5%) with hematuria. Retroperitoneal bleeding or hematuria was diagnosed in 20 patients with a mean AML size of 74 mm (25-200 mm). Twenty-one patients were treated with angioembolization at time of diagnosis and 25 had surgery. Forty-five patients with sporadic AML (mean size 34 mm) and six with TSC (mean size 120 mm) were selected for AS. Only one patient with sporadic AML (46 mm) had a bleeding, whereas two of the six TSC patients had bleedings from three kidneys (AML 70-300 mm). In 25 patients (49%), the AML-size increased with 2.7 mm/year in sporadic and 5.4 mm/year in TSC-associated AML. Thirteen patients were treated with AE (including all six TSC-patients) and five with surgery in 22 kidneys due to AML-size in 16, bleeding in four and suspicion of cancer in two.Conclusion: Bleeding occurred in 20% of AML at presentation. In patients selected for AS, we found a very low risk of bleeding in sporadic AML justifying our cut off size of 50 mm to trigger intervention. In TSC-associated AML individually tailored follow-up is needed due to a higher intervention rate.
