Occlusive dressing therapy using dimethyl sulfoxide in a patient presenting with primary localized amyloidosis of the urinary bladder: a case report

INTRODUCTION Amyloidosis is characterized by extracellular deposition of abnormal insoluble fibrils, which cause structural and functional disorders. Amyloidosis is classified into primary and secondary disease. We report a case of localized amyloidosis of the urinary bladder. In the English literature, this is the first case effectively treated with occlusive dressing therapy using dimethyl sulfoxide. CASE PRESENTATION A 58-year-old Japanese woman was introduced to our department with asymptomatic gross hematuria. Cystoscopy revealed a gently raised nodule at the right lateral wall. Histopathological findings of this lesion revealed extensive amorphous eosinophilic deposits that stained positive with Congo red and Dylon. The patient was diagnosed with primary localized amyloidosis of the urinary bladder. To treat residual amyloidosis of the bladder, we performed occlusive dressing therapy using dimethyl sulfoxide. After treatment, cystoscopy and magnetic resonance imaging showed no relapse of the mass-like lesion of the bladder wall. CONCLUSIONS Occlusive dressing therapy using dimethyl sulfoxide is efficacious and tolerable for amyloidosis of the urinary bladder. The maneuver of occlusive dressing therapy was simpler and easier than that of intravesical instillation, and occlusive dressing therapy was advantageous in that the patient could perform the therapy herself every day. However, invasive surgical management including cystectomy should be considered if conservative management is inefficacious.