During surgery for a benign cyst on the kidney, the surgeon notes that the patient’s right kidney has two ureters and two renal pelvis. This malformation is
**Core Concept**
The question is testing the student's knowledge of renal embryology and the development of the urinary system. Specifically, it's asking about the formation of the ureters and renal pelvis. During embryonic development, the ureteric bud and the metanephric mesenchyme interact to form the renal collecting system. Abnormalities in this process can lead to malformations.
**Why the Correct Answer is Right**
The correct answer is related to a rare congenital anomaly where the ureteric bud fails to properly canalize, resulting in the formation of two ureters and two renal pelvis. This condition is known as **duplex kidneys** or **bifid renal pelvis**. The ureteric bud is responsible for the formation of the renal collecting system, including the renal pelvis and calyces. In duplex kidneys, there are two separate ureters and two renal pelvis, which can lead to complications such as urinary tract infections, obstruction, and hydronephrosis.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it doesn't describe a known congenital anomaly of the kidney. There is no such condition as "bifid ureters" in the medical literature.
* **Option B:** This option is incorrect because it describes a condition where one ureter is absent, which is known as **renal agenesis**. However, in the given scenario, there are two ureters and two renal pelvis.
* **Option C:** This option is incorrect because it describes a condition where the renal pelvis is divided into two parts, but there is only one ureter. This is not the case in duplex kidneys.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that duplex kidneys can be associated with other congenital anomalies, such as horseshoe kidneys, ectopic kidneys, or ureteropelvic junction obstruction. A high index of suspicion is required to diagnose this condition, and further imaging studies such as ultrasound or CT scans may be necessary to confirm the diagnosis.
**Correct Answer:** C.