[Primary amyloidosis localized in the bladder].

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.