Question
The fetal kidneys show no obvious enlargement of the renal pelvis. Is there a problem? Please explain.
Answer
The renal pelvis shows no obvious enlargement, with no change in the thickness of the renal calyces. The renal parenchyma has no change in thickness, and there is mild expansion of the renal pelvis and calyces. The papillae are flattened or club-shaped. The renal parenchyma is thicker than normal by 3/4, indicating renal stage three. The infundibulum and pelvis are significantly expanded, with material thinning but still greater than half the normal thickness. Stage four is characterized by cystic dilation of the renal calyces, with thinning but still 1/4 thicker than normal. Stage five involves extreme expansion of the renal pelvis and calyces, with complete integration or only a thin, incomplete septum. The renal parenchyma atrophies to a thin type. Generally speaking, the problem is not significant.