Long-Term Outcomes of Sporadic Renal Angiomyolipoma: A Case Series

Chien-Wei Huang ； Chih-Yang Hsu ； Hua-Chang Fang ； Po-Tsang Lee ； Chien-Liang Chen ； Hsin-Yu Chen ； Kang-Ju Chou

《Acta Nephrologica》 32卷1期 (2018/03) Pp. 21-29

https://doi.org/10.6221/AN.201803_32(1).0004

摘要

BACKGROUND: Renal angiomyolipoma (AML) poses a potentially serious risk of retroperitoneal hemorrhage and malignant transformation. Long-term outcomes of sporadic renal AML and the timing of prophylactic intervention remain elusive. METHODS: A case series study was conducted from July 2007, through February 2010. Patients with sporadic renal AML identified by ultrasound were included. Characteristics of the enrolled patients and long-term outcomes of sporadic renal AML including the tumor growth rate, retroperitoneal hemorrhage, malignant transformation, and misdiagnosis were recorded and analyzed. The possibility of malignancy in the enrolled patients was calculated and compared with that in the general outpatient population. RESULTS: One hundred and sixty-one patients with sporadic renal AML identified by ultrasound were included in the study with the prevalence rate of 0.28%. Long-term outcomes were evaluated in 135 follow-up patients with mean follow-up of 57 months. The renal AML ≥ 4 cm in diameter had a higher proportion of clinical symptoms than that ＜ 4 cm in diameter, and was associated with the tumor growth rate (β = 0.305; 95% confidence interval [CI], 0.258 to 0.926; P = 0.001). There was no retroperitoneal hemorrhage or malignant transformation of renal AML during the study period. Renal cell carcinoma (RCC) was not detected. The prevalence of malignancy was 19.9% in the sporadic renal AML patients compared with 3.28% in the general outpatient population (relative risk, 3.20; P ＜ 0.001). Age was the significant risk factor of malignancy (Odds ratio, 1.081; 95% CI, 1.001 to 1.168; P = 0.046) in the multivariate logistic regression. CONCLUSION: Although the renal AML ≥ 4 cm in diameter was associated with clinical symptoms and the tumor growth, the timing of prophylactic intervention in patients with renal AML size ≥ 4 cm was inconclusive and should be individualized.

關鍵字

renal angiomyolipoma ； outcome ； malignancy ； malignant transformation