**Question:** All are causes of granular contracted kidney except

A. Hypertension
B. Glomerulonephritis
C. Polycystic kidney disease
D. Congenital anomalies of the kidney and urinary tract (CAKUT)

**Core Concept:** Granular contracted kidney is a condition characterized by a contracted kidney with granular or irregularly shaped parenchyma. It can be caused by various factors, including hypertension, glomerulonephritis, polycystic kidney disease, and congenital anomalies of the kidney and urinary tract (CAKUT).

**Why the Correct Answer is Right:**

The correct answer (D) refers to congenital anomalies of the kidney and urinary tract (CAKUT), which are abnormalities present from birth affecting the kidneys, ureters, bladder, and urethra. CAKUT can lead to kidney damage and dysfunction but typically does not result in granular contracted kidney morphology.

**Why Each Wrong Option is Incorrect:**

A. Hypertension (option A) can lead to chronic kidney disease and potentially cause kidney atrophy, but it does not result in granular contracted kidney morphology, which is characterized by irregularly shaped parenchyma.

B. Glomerulonephritis (option B) is an inflammation of the glomerulus, leading to kidney damage and dysfunction. It can cause kidney atrophy, but not granular contracted kidney morphology.

C. Polycystic kidney disease (option C) is a genetic disorder characterized by the formation of multiple cysts in the kidneys, leading to kidney enlargement rather than contraction and granular morphology.

**Clinical Pearl:** Understanding the distinct morphological features and etiologies of kidney diseases is essential for accurate diagnosis and appropriate treatment planning. Granular contracted kidney is a rare condition, and knowledge of common causes like hypertension and glomerulonephritis aids in differentiating and diagnosing rare conditions like this one.