Source of diagnostic pitfalls in renal sonography.

In the evaluation of 116 renal masses 91 (80%) were interpreted as cystic and 25 (20%) as solid. Additional evaluation by arteriography and finally surgery showed that 3 of the 25 initially believed to be solid proved to be cystic. These three renal masses with internal echoes on ultrasound were found at surgery to be either collections of contiguous cysts or loculated cysts with calcification. These conditions are believed to represent a source of diagnostic pitfalls in renal sonography.