[A Case of Hemodialysis-Associated Pelvic Amyloidoma Mimicking Renal Cancer-Associated Etiology].

Patients with renal insufficiency receiving long-term hemodialysis often develop so-called hemodialysis amyloidosis characterized by systemic β 2-microglobulin amyloid lesions, while patients with renal cell carcinoma may develop amyloid A(AA) amyloidosis. Herein, we present a 67-year-old man on thirty-yearlong hemodialysis who was diagnosed to have left renal cell carcinoma coincident with a large spaceoccupying lesion adjacent to the psoas muscle in the pelvic cavity. An ultrasound-guided percutaneous needle biopsy was performed at the time of laparoscopic radical nephrectomy. The pathological work-up on the needle biopsy specimen revealed that the lesion was not an AA amyloidoma but a β2-microglobulin amyloidoma, which is a rare manifestation of hemodialysis amyloidosis.