Gross hematuria: Renal cell carcinoma mimicking a renal arteriovenous malformation

The differential diagnosis between renal arteriovenous malformations (AVM) and cancer may be a challenge, due to the similar clinical and imaging findings. Herein, we report the case of an 80-year-old male patient presenting gross hematuria, initially diagnosed and treated with embolization for a renal AVM. Due to the recurrence of hematuria and rapid progression and changes of the vascular lesion with detection also of an intralesional solid nodule, a radical nephrectomy was performed revealing the presence of a renal cell carcinoma (RCC). Renal cell carcinoma and renal AVM can be difficult to differentiate from one another, for this reason a short-term follow-up should be carried out in patients diagnosed and treated for renal AVM to confirm the resolution of AVM or to assess any changes, such as atypical neovascularization or intralesional renal masses, which may increase the suspect of a hidden renal tumor.