Crossed renal ectopia and asymmetric fused kidney, with special reference to associated vertebral anomalies.

Crossed renal ectopia and/or asymmetric fused kidney are unusual congenital anomalies. The deformity itself usually produces no symptoms and the clinical presentation generally suggests obstruction and infection. In our series, 10 of 11 patients presented with various vertebral anomalies. A theory of embryogenesis was reviewed to explain asymmetric patterns of renal fusion with special reference to vertebral anomalies.