Polycystic horseshoe kidney.

Horseshoe kidney is a renal fusion anomaly during embryogenesis. The reported incidence of horseshoe kidney varies from 1 in 400 to 1 in 1,800 live births (commonly quoted 1 per 400) [Wilson and Azmy 1986]. Adult polycystic kidney disease is a hereditary disorder with autosomal-dominant transmission. Its incidence is approximately one in every 1,000-5,000 cases [Levine et al. 1997]. Polycystic horseshoe kidney is a very rare occurrence with incidence ranges of 1 in 134,000 to 1 in 8,000,000 cases [Brum et al. 1997]. We add another case to the literature.