[Renal hyperechogenicity associated with an obstructive urologic disease in the newborn infant. A case].

A newborn infant exhibited bilateral hydronephrosis induced by uretero-pelvic junction syndrome (U.J.S.), pathological renal hyperechogenicity, and renal dysplasia at histology. Renal hyperechogenicity rapidly improved after curative surgery of the U.J.S. and therefore could not relate to dysplasia which is irreversible. The diagnostic value of renal hyperechogenicity is discussed.