AA type primary amyloidosis of the urinary bladder: Clinical case and bibliographic review.

OBJECTIVE Amyloidosis is a disease characterised by deposition of eosinophilic hyaline material in different tissues. Urinary bladder involvement is uncommon with less than 200 cases of the primary form published in the literature. We present a new case of primary AA type amyloidosis of the urinary bladder (typical of secondary forms). METHODS A 66-year-old male was seen in the outpatient urology consultation with several-weeks history intermittent haematuria with decreased voiding urinary calibre. In addition, he had intense nocturia, 10-12 times per night, and occasional urgency. Physical examination of the abdomen and genitals was unremarkable. Urine sediment and blood tests were normal. Urine cytology studies were requested and revealed urothelial cells with no atypical cells and a moderate quantity of neutrophils and erythrocytes. Cystoscopy was performed and revealed yellowish erythematous lesions at the level of the vesicoureteric junction and the fundus. The lesions were biopsied. Pathology studies revealed urothelial mucosa with marked chronic inflammation and accumulations of amyloid-appearing hyaline material in the area of the vessels with green birefringence on polarised light. TUR of the bladder was later performed with the goal of completely resecting the lesion. The result of the pathology studies confirmed the biopsy findings and immunohistochemistry studies revealed AA type amyloid (typical of secondary forms). RESULTS Two years after the intervention, the patient remains asymptomatic with normal endoscopic follow-up studies. CONCLUSIONS Primary AA type amyloidosis of the bladder is a very uncommon pathology with few cases reported in the international urology literature. Nevertheless, we must keep it in mind in the differential diagnosis when faced with a patient with haematuria and/or persistent urinary symptoms.