[Renal inflammatory pseudotumor after embolization for arteriovenous malformation: a case report]

A 61-year-old man was admitted to our hospital with the chief complaint of asymptomatic macrohematuria. Because he was diagnosed with arteriovenous malformation of the right kidney by angiography, embolization was performed. However, 2 years and 3 months later, bleeding from the right kidney was detected. Computed tomography (CT) revealed a low density area (1.8 cm) in the right kidney protruding to the renal pelvic adjacent to the old embolized lesion. Since we could not make a conclusive diagnosis as malignant disease by ureteroscopy and angiography, we have decided to follow the case carefully. Nine months later, macroscopic hematuria worsened, and the low density area by CT in the right kidney expanded. Therefore, we finally decided to perform right total nephroureterectomy. The tumor was histologically diagnosed as renal inflammatory pseudotumor. This is the 14th case reported in Japan. We here report the renal inflammatory pseudotumor with a review of the Japanese literature.