Think twice before stent insertion for renal artery aneurysm with elusive etiology: a case report

BACKGROUND: Endovascular treatment has been recognized as the first line therapy for renal artery aneurysm (RAA). However, RAA related with malignancies had been sporadically reported in the literature. Stent insertion should be contraindicated for RAAs with malignant etiology, whereas surgery be optimal. CASE PRESENTATION: A 40-year-old female underwent covered stent insertion to exclude the left RAA for suspected Takayasu arteritis in a reginal hospital. Three months later the RAA recurred with sign of threatened rupture, and the patient was transferred for salvage embolization with coils and thrombin injection. However, 20 days after the embolization procedure, multiple painful subcutaneous nodules developed in her flanks. Undifferentiated sarcoma was revealed by the pathological biopsy of the nodules. The RAA in this case was most likely related with the malignancy. CONCLUSION: Malignancy was the most likely etiology behind recurrent aneurysm in this case. Definite diagnosis is mandatory for interventional radiologists before stent insertion for treatment of RAA.