Immaturity of renal development resulting in a lobulated renal contour is known as what?

• A. Fetal lobulation
• B. Papilla
• C. Dromedary hump
• D. Hypertrophied column of Bertin

Answer: (A)

This pattern reflects a developmental variant where the outer surface of the kidney remains divided into lobes because the calyces did not fuse completely during development. The result is a lobulated border with grooves that mark the boundaries between lobes. Often this appearance is seen in children and can persist into adulthood as a benign finding; it does not indicate disease. The other terms describe different renal features: a papilla is the tip of the renal pyramid inside the collecting system; a dromedary hump is a single lateral cortical bulge on the kidney; a hypertrophied column of Bertin is thickened renal columns that can mimic a mass but does not create a lobulated surface. Therefore, the immaturity of renal development producing a lobulated contour is fetal lobulation.