Case report on ureteral amyloidosis that was incidentally diagnosed in a patient with malignant lymphoma.

Herein, we report a rare case of localized ureteral amyloidosis in a patient with malignant lymphoma. A 73-year-old female patient visited our institution for a comprehensive examination and treatment of malignant lymphoma. Contrast-enhanced computed tomography scan and magnetic resonance imaging revealed left hydronephrosis and a left lower ureteral mass. These findings suggested either ureteral amyloidosis or a ureteral carcinoma with significant fibrosis. Cystoscopic biopsy was performed, and the patient was pathologically diagnosed with ureteral amyloidosis. Renal renography revealed left renal dysfunction. However, the patient was asymptomatic. Hence, the patient should be followed-up for ureteral amyloidosis. Computed tomography scan were performed every 3 months, and after approximately 1 year, there was no evidence of mass enlargement. This case highlights the rarity of ureteral amyloidosis and the importance of imaging diagnosis in clinical practice.