Papillary necrosis features are all except:
**Core Concept**
Papillary necrosis is a condition characterized by the necrosis of the renal papillae, which are the areas at the base of the renal pyramids. This condition is often associated with analgesic nephropathy, diabetes mellitus, and other systemic diseases.
**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of papillary necrosis, which involves the obstruction of blood flow to the renal papillae. This obstruction can occur due to the deposition of analgesic crystals, leading to ischemia and subsequent necrosis of the renal papillae. The renal papillae are composed of a dense network of blood vessels, which are susceptible to damage from analgesic crystals.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it is not a recognized feature of papillary necrosis. Papillary necrosis is often associated with the presence of blood clots and hemorrhages in the renal pelvis, but this is not a primary feature of the condition.
* **Option B:** This option is incorrect because it is not a characteristic of papillary necrosis. The renal papillae are not typically inflamed in papillary necrosis, and inflammation is not a primary feature of the condition.
* **Option C:** This option is incorrect because it is not a specific feature of papillary necrosis. While renal calculi can be associated with papillary necrosis, they are not a primary feature of the condition.
**Clinical Pearl / High-Yield Fact**
Papillary necrosis is often associated with the use of analgesic medications, particularly those containing phenacetin. This association highlights the importance of careful medication management in patients with renal disease.
**Correct Answer: C.**