Ureterocele
Ureterocele is a cystic dilatation of the intravesical portion of the bladder. Its occurrence was reported in dizygotic twins by Ayalon et al. (1979) and in monozygotic twins by Riba (1936). Abrams et al. (1980) observed the malformation in teenage brothers. In the family reported by Ayalon et al. (1979) the parents were first cousins and the father as well as a sister had double collecting systems on intravenous pyelography. DeWeerd and Feeney (1967) reported affected mother and daughter.