RESUMEN
The congenital renal cystic disease encompasses a complex group of pathologic and clinical entities. We retrospectively reviewed 42 cases of congenital renal cystic lesions classified into four Potter types in a series of 2,063 consecutive autopsies from 1981 to 1996. According to our study based on morphologic, clinical, genetic features and associated anomalies, type I and III are relatively compatible with Potter's original definition. However, it was reasonable that type II and IV are classified to the same group because of: 1) very similar histologic findings representing dysplastic kidney, 2) many associated anomalies, 3) no evidence of inheritance, and 4) presence of a combined type. Syndrome associated cysts, such as Meckel-Gruber syndrome, were also separately classified. If the dysplastic evidence was insufficient for diagnosis to the dysplastic kidney in type II and IV, then these cases would be better classified into a cystic disease associated with congenital hydronephrosis. We propose a classification of the congenital cystic disease of the kidney to be: 1) dysplastic kidney, 2) cystic disease associated with congenital hydronephrosis, 3) polycystic kidney, and 4) syndromic cystic disease.