Primary localized amyloidosis of the bladder: Experience with dimethyl sulfoxide therapy

Purpose: We present our long-term experience with intravesical dimethyl sulfoxide (DMSO) for primary localized amyloidosis of the bladder. Materials and Methods: The study included 4 males and 2 females 28 to 68 years old (mean age 54) at diagnosis of biopsy proven primary localized amyloidosis involving the bladder diffusely or extensively in 1 locale. All patients had normal upper urinary tracts. They continued to be symptomatic (hematuria in 3, irritative voiding symptoms in 1, and hematuria and irritative voiding symptoms in 2) despite conventional transurethral destructive therapy. Every 2 weeks they received 30-minute instillations of 50 ml. 50% DMSO intravesically for 3 months (patient 1), 6 months (1) and 1 year (4). Results: Therapy failed at 3 and 6 months in 2 patients of whom 1 with a contracted bladder underwent cystectomy and another was stabilized for 1 year with laser therapy. In the remaining 4 patients who were followed for 6 years disease stabilized for 2 to 6 years (mean 3.5) but 3 later required additional therapy including repeat DMSO in 1 and laser therapy in 2. Conclusions: Diffuse or locally extensive bladder involvement by primary localized amyloidosis usually fails to respond to conventional transurethral destructive surgical procedures. Collectively, our experience and the literature suggest that intravesical DMSO can be a bladder saving measure and help resolve ureterovesical obstruction in some patients. High recurrence rate mandates lifelong cystoscopic surveillance.