Sporadic Balkan Endemic Nephropathy (BEN) beyond the known regions of BEN

There is an very old opinion that we diagnose only most prominent BEN cases and miss latent and mild ones, that unrecognized BEN is possible in endemic villages and the number of such cases, their characteristics, and origin are unknown. From 1955 to 1998 year we evaluated 1235 patients with histologicaly proven upper urothelial tumors, who underwent surgery. The diagnosis of sporadic BEN, was made after exclusion of other known nephropaties. In the analyzed region, BEN was present in 170 of 808 settlements, and in 104 of them, 534 cases of UUT were reported. In 66 possible BEN settlements, there were no UUT cases. In the next 457 of 808 settlements (56.6%) neither BEN, or UUT were registered. Sporadic BEN is an atypical, mild clinical variety of BEN, with simultaneous presence of UUT. Both sexes were equally affected, with the majority of patients in sixth and seventh decade of. The presence of sporadic BEN cases gives a possibility to speculate that the existence of BEN without familiar agreggations is possible elsevere, not only in Balkans.