Kidney tissue displaced by cysts of varying sizes, usually unilateral is which condition?

• A. Multicystic dysplastic kidney
• B. Wilms tumor
• C. Sacrococcygeal teratoma
• D. Omphalocele

Answer: (A)

The situation described—kidney tissue displaced by cysts of varying sizes and usually on one side—points to multicystic dysplastic kidney. In this condition, normal renal parenchyma is replaced by a cluster of nonfunctional cysts of different sizes, reflecting disorganized development of the kidney. The affected kidney is typically nonfunctional, and the other kidney is usually normal or slightly enlarged to compensate.

This differs from a Wilms tumor, which is a solid renal mass arising from a nephroblastoma and tends to be a single, large, heterogeneous (not simply cystic) lesion rather than a collection of multiple cysts. Sacrococcygeal teratoma occurs at the base of the tailbone outside the kidney, and an omphalocele is an abdominal wall defect with herniated viscera, not a kidney lesion.