**Question:** Bilaterally symmetrical contracted scarred kidney is seen in-

A. Chronic Kidney Disease (CKD)
B. Acute Kidney Injury (AKI)
C. Polycystic Kidney Disease (PKD)
D. Nephrectomy (kidney removal)

**Correct Answer:** D. Nephrectomy (kidney removal)

**Core Concept:** A bilaterally symmetrical contracted scarred kidney indicates the loss of renal function due to surgical removal of one or both kidneys, a process known as nephrectomy.

**Why the Correct Answer is Right:** Nephrectomy results in the complete removal of one or both kidneys, leading to a loss of renal function. Consequently, the kidney will appear contracted and scarred on imaging studies, such as ultrasound or computed tomography (CT).

**Why Each Wrong Option is Incorrect:**

A. Chronic Kidney Disease (CKD) and Acute Kidney Injury (AKI) are conditions characterized by impaired kidney function due to various etiologies like hypertension, diabetes, infections, or acute injury. In both cases, the kidneys do not show symmetrical contraction and scarring as they retain some functional units.

B. Polycystic Kidney Disease (PKD) is a genetic disorder characterized by the formation of numerous fluid-filled cysts in both kidneys, leading to enlargement, not contraction and scarring.

**Clinical Pearl:** In clinical practice, recognizing the cause of bilaterally contracted and scarred kidneys is essential to initiate proper management strategies for patients with impaired renal function. These causes can have different therapeutic approaches, and understanding the underlying pathology helps in formulating a targeted treatment plan.