ABSTRACT
OBJECTIVE: We report a case of localized amyloidosis of the urinary bladder in an 80-year-old female whose main presenting symptom was massive hematuria. METHODS: Cystoscopic examination revealed a tumor on the trigone and bladder neck. A transurethral resection of the tumor was performed and the fragments were processed for histopathological study with hematoxylin-eosin and Congo red staining and ultrastructural study. RESULTS: The histopathological analyses disclosed large eosinophilic deposits in the submucosa with birefringence under polarized light in Congo red staining. Electron microscopy revealed a meshwork of filaments typical of amyloid. The patient had no symptoms or signs of systemic disease and remains symptom-free four years later. CONCLUSIONS: Primary localized amyloidosis of the urinary bladder is a rare condition that can be successfully treated surgically and has an excellent prognosis.
