[Amyloidosis of the urethra: a case report].

A 26-year-old man was introduced to our hospital with a complaint of macrohematuria. Endoscopic examination showed a small tumor in the anterior urethra. Microscopic examination of a biopsy specimen taken under lumbar anesthesia showed amyloid deposition in the urethral submucosa. On Congo red staining, amyloid was visualized as orange material, showing characteristic birefringence under polarized light. Amyloidosis of the urethra was diagnosed. Because the patient refused to undergo duodenal or rectal biopsy, the possibility of systemic amyloidosis could not be completely excluded. No recurrence has been noted since the endoscopic examination, and no further symptoms have been reported.