[Alkaline-urine incrusted cystitis. Clinical aspects and treatment].

The authors report 2 cases of a condition often overlooked by the urologist: incrusted cystitis. It shows up clinically with severe urinary troubles and bladder calcifications. In fact the main finding is calcified plaques in the mucosa causing an inflammatory reaction and mimicking a tumor. Histologic examination of endoscopic biopsies rules out tumor and reveals a calcified necrotic mucosa. A high degree of alkalinity of the urine makes the diagnosis of incrusted cystitis after ruling out tuberculosis and bilharziasis. Acidifying the urine clears up the trouble and brings the bladder mucosa back to normal. According to the literature, 3 factors are necessary for the development of incrusted cystitis: a ureolytic microbe capable of releasing ammonia, alkalinity of the urine resulting from this, and a bladder with lesions of cystitis whatever might be the cause. A number of diagnostic errors are possible, but the most serious one is mistaking it for a calcified malignant tumor of the bladder. For this a biopsy is essential to prove the absence of a tumor. The treatment consists of 3 stages: excision of the calcified plaques (mostly by endoscopy), sterilization of the urine (nalidixic acid would be the best agent) and acidification of the urine.