Characteristics of urinary tract tumours in the area of Balkan endemicnephropathy in Croatia.

There is a general consensus that the incidence of urothelial tumours is much higher among the inhabitants of areas of Balkan endemic nephropathy than in populations in nonendemic areas. Data from different authors on tumour incidences in unrelated endemic areas in various countries vary widely, however. Lack of understanding of the possible etiological relationship between Balkan endemic nephropathy and the increased incidence of urothelial tumours justifies efforts to conduct retrospective studies using unique diagnostic criteria. In order to investigate the occurrence of urinary tract tumours in Slavonski Brod, a part of which has a high incidence of nephropathy, a retrospective study was carried out using data and tissue samples collected at the Department of Pathology and Forensic Medicine of the Slavonski Brod Medical Centre. During the last 16 years, 193 urinary tumours from the county were examined; the material available consisted of autopsy reports and surgical and biopsy specimens. Tumours were diagnosed histologically and coded according to guidelines of the WHO and US registries, as papillomas, papillary and solid carcinomas of the transitional-cell type, squamous-cell carcinomas and carcinomas in situ. A 5.1 times higher incidence of urothelial tumours was seen among inhabitants of the nephropathic area of the county than in nonendemic areas. Tumours from cases in the endemic region also tended more often to be malignant and multiple; they were not infrequently bilateral.